feat: add color search and reusable tooltips

Add dominant-color palette extraction, storage, filtering, and startup backfill so the gallery and Timeline can be filtered from the toolbar color picker.

Introduce a reusable tooltip component and migrate the color filter, update indicator, and gallery filename hover affordances to it.

CHANGELOG.md

@@ -9,6 +9,9 @@ aims to follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html)
 
 ### Added
 
+- **Color search** — filter the gallery (and Timeline) by dominant color via a
+  collapsible swatch palette plus a custom color picker in the toolbar; existing
+  libraries are backfilled automatically in the background.
 - **Albums** — curate your own collections. A new Albums section in the sidebar
   (with cover thumbnails, kept visually distinct from Libraries) lets you create,
   rename, and open albums; albums can span multiple folders. Add images from the

src-tauri/src/color.rs

@@ -0,0 +1,91 @@
+//! Dominant-color palette extraction for color search.
+//!
+//! Colors are sampled from the already-generated thumbnail (small, fast) rather
+//! than the full image. We coarse-quantize pixels into an RGB histogram, then
+//! return the most populated bins as representative colors with their weight
+//! (fraction of sampled pixels). Search then filters images whose palette has a
+//! color within a distance threshold of the query color.
+
+use image::RgbImage;
+use std::collections::HashMap;
+use std::path::Path;
+
+#[derive(Debug, Clone, Copy)]
+pub struct PaletteColor {
+    pub r: u8,
+    pub g: u8,
+    pub b: u8,
+    /// Fraction of sampled pixels (0.0–1.0) that fell in this color's bin.
+    pub weight: f32,
+}
+
+/// Bits kept per channel when binning. 4 bits → 16 levels/channel → 4096 bins:
+/// coarse enough to group near-identical shades, fine enough to separate hues.
+const QUANT_BITS: u32 = 4;
+/// Cap on sampled pixels so very large frames stay cheap; thumbnails are tiny so
+/// this rarely bites, but the backfill may read arbitrary thumbnail sizes.
+const MAX_SAMPLES: usize = 50_000;
+
+/// Extract up to `k` dominant colors from an RGB image, most-common first.
+pub fn extract_palette(img: &RgbImage, k: usize) -> Vec<PaletteColor> {
+    let pixels = img.as_raw();
+    let pixel_count = pixels.len() / 3;
+    if pixel_count == 0 {
+        return Vec::new();
+    }
+    let step = (pixel_count / MAX_SAMPLES).max(1);
+    let shift = 8 - QUANT_BITS;
+
+    // bin key → (sum_r, sum_g, sum_b, count); summing lets us return the bin's
+    // average color rather than the quantized corner.
+    let mut bins: HashMap<u16, (u64, u64, u64, u64)> = HashMap::new();
+    let mut total: u64 = 0;
+    for pixel in pixels.chunks_exact(3).step_by(step) {
+        let (r, g, b) = (pixel[0], pixel[1], pixel[2]);
+        let key = (((r as u16) >> shift) << (QUANT_BITS * 2))
+            | (((g as u16) >> shift) << QUANT_BITS)
+            | ((b as u16) >> shift);
+        let entry = bins.entry(key).or_insert((0, 0, 0, 0));
+        entry.0 += r as u64;
+        entry.1 += g as u64;
+        entry.2 += b as u64;
+        entry.3 += 1;
+        total += 1;
+    }
+    if total == 0 {
+        return Vec::new();
+    }
+
+    let mut entries: Vec<(u64, u64, u64, u64)> = bins.into_values().collect();
+    entries.sort_unstable_by_key(|entry| std::cmp::Reverse(entry.3));
+    entries
+        .into_iter()
+        .take(k)
+        .map(|(sum_r, sum_g, sum_b, count)| PaletteColor {
+            r: (sum_r / count) as u8,
+            g: (sum_g / count) as u8,
+            b: (sum_b / count) as u8,
+            weight: count as f32 / total as f32,
+        })
+        .collect()
+}
+
+/// Decode a thumbnail file and extract its palette. Used by the backfill pass.
+pub fn extract_palette_from_file(thumbnail_path: &Path, k: usize) -> Option<Vec<PaletteColor>> {
+    let img = image::ImageReader::open(thumbnail_path)
+        .ok()?
+        .decode()
+        .ok()?;
+    Some(extract_palette(&img.into_rgb8(), k))
+}
+
+/// Number of palette colors stored per image.
+pub const PALETTE_SIZE: usize = 5;
+
+/// Max squared RGB distance for a palette color to count as matching a query
+/// color (~70 units in RGB space). Tunable feel/precision of color search.
+pub const MATCH_DISTANCE_SQ: i64 = 4900;
+
+/// Minimum weight (fraction of pixels) a palette color must have to match, so
+/// trivial specks of a color don't trigger a match.
+pub const MATCH_MIN_WEIGHT: f64 = 0.05;

src-tauri/src/commands.rs

@@ -42,6 +42,9 @@ pub struct GetImagesParams {
     pub rating_min: Option<i64>,
     pub embedding_failed_only: Option<bool>,
     pub tagging_failed_only: Option<bool>,
+    /// Optional `[r, g, b]` color filter — matches images whose palette contains
+    /// a prominent color near this one.
+    pub color: Option<[u8; 3]>,
     pub sort: Option<String>,
     pub offset: Option<i64>,
     pub limit: Option<i64>,
@@ -564,6 +567,7 @@ pub async fn get_images(
     let rating_min = params.rating_min.unwrap_or(0);
     let embedding_failed_only = params.embedding_failed_only.unwrap_or(false);
     let tagging_failed_only = params.tagging_failed_only.unwrap_or(false);
+    let color = params.color.map(|[r, g, b]| (r, g, b));
 
     let total = db::count_images(
         &conn,
@@ -574,6 +578,7 @@ pub async fn get_images(
         rating_min,
         embedding_failed_only,
         tagging_failed_only,
+        color,
     )
     .map_err(|e| e.to_string())?;
 
@@ -586,6 +591,7 @@ pub async fn get_images(
         rating_min,
         embedding_failed_only,
         tagging_failed_only,
+        color,
         sort,
         offset,
         limit,
@@ -2268,7 +2274,10 @@ pub async fn list_albums(db: State<'_, DbState>) -> Result<Vec<Album>, String> {
 }
 
 #[tauri::command]
-pub async fn create_album(db: State<'_, DbState>, params: CreateAlbumParams) -> Result<Album, String> {
+pub async fn create_album(
+    db: State<'_, DbState>,
+    params: CreateAlbumParams,
+) -> Result<Album, String> {
     let conn = db.get().map_err(|e| e.to_string())?;
     let name = params.name.trim();
     if name.is_empty() {
@@ -2294,13 +2303,19 @@ pub async fn delete_album(db: State<'_, DbState>, params: DeleteAlbumParams) ->
 }
 
 #[tauri::command]
-pub async fn reorder_albums(db: State<'_, DbState>, params: ReorderAlbumsParams) -> Result<(), String> {
+pub async fn reorder_albums(
+    db: State<'_, DbState>,
+    params: ReorderAlbumsParams,
+) -> Result<(), String> {
     let conn = db.get().map_err(|e| e.to_string())?;
     db::reorder_albums(&conn, &params.album_ids).map_err(|e| e.to_string())
 }
 
 #[tauri::command]
-pub async fn delete_albums(db: State<'_, DbState>, params: DeleteAlbumsParams) -> Result<(), String> {
+pub async fn delete_albums(
+    db: State<'_, DbState>,
+    params: DeleteAlbumsParams,
+) -> Result<(), String> {
     let conn = db.get().map_err(|e| e.to_string())?;
     db::delete_albums(&conn, &params.album_ids).map_err(|e| e.to_string())
 }

src-tauri/src/db.rs

@@ -321,6 +321,17 @@ pub fn migrate(conn: &Connection) -> Result<()> {
 
         CREATE INDEX IF NOT EXISTS idx_album_images_album ON album_images(album_id);
         CREATE INDEX IF NOT EXISTS idx_album_images_image ON album_images(image_id);
+
+        CREATE TABLE IF NOT EXISTS image_colors (
+            image_id INTEGER NOT NULL REFERENCES images(id) ON DELETE CASCADE,
+            idx      INTEGER NOT NULL,
+            r        INTEGER NOT NULL,
+            g        INTEGER NOT NULL,
+            b        INTEGER NOT NULL,
+            weight   REAL NOT NULL,
+            PRIMARY KEY (image_id, idx)
+        );
+        CREATE INDEX IF NOT EXISTS idx_image_colors_image ON image_colors(image_id);
         ",
     )?;
 
@@ -1741,11 +1752,7 @@ pub fn add_images_to_album(conn: &Connection, album_id: i64, image_ids: &[i64])
     Ok(added)
 }
 
-pub fn remove_images_from_album(
-    conn: &Connection,
-    album_id: i64,
-    image_ids: &[i64],
-) -> Result<()> {
+pub fn remove_images_from_album(conn: &Connection, album_id: i64, image_ids: &[i64]) -> Result<()> {
     let tx = conn.unchecked_transaction()?;
     for image_id in image_ids {
         tx.execute(
@@ -1872,6 +1879,63 @@ pub fn bulk_remove_tag_by_name(conn: &Connection, image_ids: &[i64], tag: &str)
     Ok(())
 }
 
+// ── Color palettes (color search) ──────────────────────────────────────────────
+
+/// Replace an image's stored color palette. `colors` is `(r, g, b, weight)`.
+pub fn replace_image_colors(
+    conn: &Connection,
+    image_id: i64,
+    colors: &[(u8, u8, u8, f32)],
+) -> Result<()> {
+    conn.execute("DELETE FROM image_colors WHERE image_id = ?1", [image_id])?;
+    for (idx, (r, g, b, weight)) in colors.iter().enumerate() {
+        conn.execute(
+            "INSERT INTO image_colors (image_id, idx, r, g, b, weight)
+             VALUES (?1, ?2, ?3, ?4, ?5, ?6)",
+            params![
+                image_id,
+                idx as i64,
+                *r as i64,
+                *g as i64,
+                *b as i64,
+                *weight as f64
+            ],
+        )?;
+    }
+    Ok(())
+}
+
+/// Images (with thumbnails) that have no stored palette yet — the backfill set.
+/// Returns `(image_id, thumbnail_path)`.
+pub fn get_images_missing_colors(conn: &Connection, limit: i64) -> Result<Vec<(i64, String)>> {
+    let mut stmt = conn.prepare(
+        "SELECT i.id, i.thumbnail_path
+         FROM images i
+         WHERE i.media_kind = 'image'
+           AND i.thumbnail_path IS NOT NULL
+           AND NOT EXISTS (SELECT 1 FROM image_colors c WHERE c.image_id = i.id)
+         LIMIT ?1",
+    )?;
+    let rows = stmt.query_map([limit], |row| {
+        Ok((row.get::<_, i64>(0)?, row.get::<_, String>(1)?))
+    })?;
+    Ok(rows.collect::<rusqlite::Result<Vec<_>>>()?)
+}
+
+/// Count of images still awaiting palette extraction (for backfill progress).
+pub fn count_images_missing_colors(conn: &Connection) -> Result<i64> {
+    let count = conn.query_row(
+        "SELECT COUNT(*)
+         FROM images i
+         WHERE i.media_kind = 'image'
+           AND i.thumbnail_path IS NOT NULL
+           AND NOT EXISTS (SELECT 1 FROM image_colors c WHERE c.image_id = i.id)",
+        [],
+        |row| row.get(0),
+    )?;
+    Ok(count)
+}
+
 pub fn repair_deferred_embedding_jobs(conn: &Connection) -> Result<usize> {
     let pattern = "No thumbnail available yet for%";
     let repaired = conn.execute(
@@ -1999,6 +2063,7 @@ pub fn get_images(
     rating_min: i64,
     embedding_failed_only: bool,
     tagging_failed_only: bool,
+    color: Option<(u8, u8, u8)>,
     sort: &str,
     offset: i64,
     limit: i64,
@@ -2023,6 +2088,10 @@ pub fn get_images(
     let favorites_flag = i64::from(favorites_only);
     let embedding_failed_flag = i64::from(embedding_failed_only);
     let tagging_failed_flag = i64::from(tagging_failed_only);
+    let (color_flag, qr, qg, qb) = match color {
+        Some((r, g, b)) => (1i64, r as i64, g as i64, b as i64),
+        None => (0, 0, 0, 0),
+    };
     let sql = format!(
         "SELECT id, folder_id, path, filename, thumbnail_path, width, height, file_size, created_at, modified_at, taken_at, mime_type,
                 media_kind, duration_ms, video_codec, audio_codec, metadata_updated_at, metadata_error,
@@ -2037,6 +2106,12 @@ pub fn get_images(
            AND rating >= ?5
            AND (?6 = 0 OR embedding_status = 'failed')
            AND (?7 = 0 OR ai_tagger_error IS NOT NULL)
+           AND (?10 = 0 OR EXISTS (
+               SELECT 1 FROM image_colors c
+               WHERE c.image_id = images.id
+                 AND c.weight >= ?15
+                 AND ((c.r - ?11)*(c.r - ?11) + (c.g - ?12)*(c.g - ?12) + (c.b - ?13)*(c.b - ?13)) <= ?14
+           ))
          ORDER BY {order}
          LIMIT ?8 OFFSET ?9"
     );
@@ -2051,7 +2126,13 @@ pub fn get_images(
             embedding_failed_flag,
             tagging_failed_flag,
             limit,
-            offset
+            offset,
+            color_flag,
+            qr,
+            qg,
+            qb,
+            crate::color::MATCH_DISTANCE_SQ,
+            crate::color::MATCH_MIN_WEIGHT
         ],
         map_image_row,
     )?;
@@ -2068,12 +2149,17 @@ pub fn count_images(
     rating_min: i64,
     embedding_failed_only: bool,
     tagging_failed_only: bool,
+    color: Option<(u8, u8, u8)>,
 ) -> Result<i64> {
     let search_pattern = search.map(|value| format!("%{value}%"));
 
     let favorites_flag = i64::from(favorites_only);
     let embedding_failed_flag = i64::from(embedding_failed_only);
     let tagging_failed_flag = i64::from(tagging_failed_only);
+    let (color_flag, qr, qg, qb) = match color {
+        Some((r, g, b)) => (1i64, r as i64, g as i64, b as i64),
+        None => (0, 0, 0, 0),
+    };
     let count = conn.query_row(
         "SELECT COUNT(*) FROM images
          WHERE (?1 IS NULL OR folder_id = ?1)
@@ -2082,7 +2168,13 @@ pub fn count_images(
            AND (?4 = 0 OR favorite = 1)
            AND rating >= ?5
            AND (?6 = 0 OR embedding_status = 'failed')
-           AND (?7 = 0 OR ai_tagger_error IS NOT NULL)",
+           AND (?7 = 0 OR ai_tagger_error IS NOT NULL)
+           AND (?8 = 0 OR EXISTS (
+               SELECT 1 FROM image_colors c
+               WHERE c.image_id = images.id
+                 AND c.weight >= ?13
+                 AND ((c.r - ?9)*(c.r - ?9) + (c.g - ?10)*(c.g - ?10) + (c.b - ?11)*(c.b - ?11)) <= ?12
+           ))",
         params![
             folder_id,
             search_pattern,
@@ -2090,7 +2182,13 @@ pub fn count_images(
             favorites_flag,
             rating_min,
             embedding_failed_flag,
-            tagging_failed_flag
+            tagging_failed_flag,
+            color_flag,
+            qr,
+            qg,
+            qb,
+            crate::color::MATCH_DISTANCE_SQ,
+            crate::color::MATCH_MIN_WEIGHT
         ],
         |row| row.get(0),
     )?;

src-tauri/src/indexer.rs

@@ -190,6 +190,13 @@ pub struct MediaUpdateBatch {
     pub images: Vec<ImageRecord>,
 }
 
+#[derive(Clone, Serialize)]
+pub struct ColorBackfillProgress {
+    pub processed: i64,
+    pub total: i64,
+    pub done: bool,
+}
+
 #[derive(Clone, Serialize)]
 pub struct MediaJobProgressEvent {
     pub progress: Vec<FolderJobProgress>,
@@ -737,6 +744,13 @@ fn persist_thumbnail_results(
                     width,
                     height,
                 )?);
+
+                // Store the dominant-color palette sampled during resizing.
+                if let Some(thumb) = &generated {
+                    if !thumb.palette.is_empty() {
+                        db::replace_image_colors(&tx, image_id, &thumb.palette)?;
+                    }
+                }
             }
 
             tx.commit()?;
@@ -767,6 +781,76 @@ fn is_avif_path(path: &Path) -> bool {
         .is_some_and(|ext| ext.eq_ignore_ascii_case("avif"))
 }
 
+/// One-shot background pass that samples a color palette from the (already
+/// generated) thumbnails of images indexed before color search existed. New
+/// images get their palette during thumbnail generation, so this only fills the
+/// historical gap. Emits `color-backfill-progress` so the UI can show a count.
+pub fn start_color_backfill(app: AppHandle, pool: DbPool) {
+    std::thread::spawn(move || {
+        let total = match pool.get() {
+            Ok(conn) => db::count_images_missing_colors(&conn).unwrap_or(0),
+            Err(_) => return,
+        };
+        if total == 0 {
+            return;
+        }
+        log::info!("Color backfill: sampling palettes for {total} images.");
+
+        let mut processed: i64 = 0;
+        loop {
+            let batch = match pool.get() {
+                Ok(conn) => db::get_images_missing_colors(&conn, 64).unwrap_or_default(),
+                Err(_) => break,
+            };
+            if batch.is_empty() {
+                break;
+            }
+
+            for (image_id, thumbnail_path) in batch {
+                let palette = crate::color::extract_palette_from_file(
+                    Path::new(&thumbnail_path),
+                    crate::color::PALETTE_SIZE,
+                );
+                let colors: Vec<(u8, u8, u8, f32)> = match palette {
+                    Some(colors) if !colors.is_empty() => colors
+                        .into_iter()
+                        .map(|c| (c.r, c.g, c.b, c.weight))
+                        .collect(),
+                    // Unreadable thumbnail: store a zero-weight sentinel so the
+                    // image isn't reprocessed forever (it just won't match).
+                    _ => vec![(0, 0, 0, 0.0)],
+                };
+                let _ = with_db_write_lock(|| {
+                    let conn = pool.get()?;
+                    db::replace_image_colors(&conn, image_id, &colors)
+                });
+                processed += 1;
+            }
+
+            let _ = app.emit(
+                "color-backfill-progress",
+                ColorBackfillProgress {
+                    processed,
+                    total,
+                    done: false,
+                },
+            );
+            // Yield so the backfill stays in the background under active use.
+            std::thread::sleep(Duration::from_millis(15));
+        }
+
+        log::info!("Color backfill complete: {processed} images sampled.");
+        let _ = app.emit(
+            "color-backfill-progress",
+            ColorBackfillProgress {
+                processed,
+                total,
+                done: true,
+            },
+        );
+    });
+}
+
 /// Returns `Ok(true)` if a batch was claimed and processed, `Ok(false)` if
 /// the queue was empty.
 fn process_metadata_batch(

src-tauri/src/lib.rs

@@ -1,4 +1,5 @@
 mod captioner;
+mod color;
 mod commands;
 mod db;
 mod embedder;
@@ -122,6 +123,8 @@ pub fn run() {
             // Caption worker disabled — UI removed; keeping backend code intact for future use.
             // indexer::start_caption_worker(app.handle().clone(), pool.clone(), app_dir.clone());
             indexer::start_tagging_worker(app.handle().clone(), pool.clone(), app_dir.clone());
+            // Backfill color palettes for images indexed before color search existed.
+            indexer::start_color_backfill(app.handle().clone(), pool.clone());
 
             let watcher_handle = indexer::start_watcher(app.handle().clone(), pool.clone(), thumb_dir.clone());
 

src-tauri/src/thumbnail.rs

@@ -12,6 +12,9 @@ pub struct GeneratedThumbnail {
     pub path: PathBuf,
     pub width: Option<i64>,
     pub height: Option<i64>,
+    /// Dominant-color palette `(r, g, b, weight)` sampled while resizing. Empty
+    /// when the thumbnail already existed (the color backfill handles those).
+    pub palette: Vec<(u8, u8, u8, f32)>,
 }
 
 pub fn generate_image_thumbnail(image_path: &Path, cache_dir: &Path) -> Result<GeneratedThumbnail> {
@@ -28,6 +31,7 @@ pub fn generate_image_thumbnail(image_path: &Path, cache_dir: &Path) -> Result<G
             path: out_path,
             width: original_dimensions.0,
             height: original_dimensions.1,
+            palette: Vec::new(),
         });
     }
 
@@ -47,6 +51,12 @@ pub fn generate_image_thumbnail(image_path: &Path, cache_dir: &Path) -> Result<G
     let thumb = image::RgbImage::from_raw(dst_width, dst_height, dst.buffer().to_vec())
         .ok_or_else(|| anyhow!("failed to construct resized thumbnail buffer"))?;
 
+    // Sample the dominant-color palette from the resized buffer before encoding.
+    let palette = crate::color::extract_palette(&thumb, crate::color::PALETTE_SIZE)
+        .into_iter()
+        .map(|color| (color.r, color.g, color.b, color.weight))
+        .collect();
+
     if let Some(parent) = out_path.parent() {
         std::fs::create_dir_all(parent)?;
     }
@@ -58,6 +68,7 @@ pub fn generate_image_thumbnail(image_path: &Path, cache_dir: &Path) -> Result<G
         path: out_path,
         width: original_dimensions.0,
         height: original_dimensions.1,
+        palette,
     })
 }
 
@@ -166,6 +177,7 @@ pub fn generate_video_thumbnail(
             path: out_path,
             width: None,
             height: None,
+            palette: Vec::new(),
         });
     }
 
@@ -231,6 +243,7 @@ pub fn generate_video_thumbnail(
                 path: out_path,
                 width: None,
                 height: None,
+                palette: Vec::new(),
             });
         }
         last_error = String::from_utf8_lossy(&output.stderr).to_string();
@@ -255,6 +268,7 @@ pub fn generate_avif_thumbnail(
             path: out_path,
             width: original_dimensions.0,
             height: original_dimensions.1,
+            palette: Vec::new(),
         });
     }
 
@@ -282,10 +296,19 @@ pub fn generate_avif_thumbnail(
         .output()?;
 
     if output.status.success() && out_path.exists() {
+        // AVIF is decoded by FFmpeg, so there's no in-memory RGB buffer here;
+        // sample the palette by reading the JPEG thumbnail we just wrote.
+        let palette =
+            crate::color::extract_palette_from_file(&out_path, crate::color::PALETTE_SIZE)
+                .unwrap_or_default()
+                .into_iter()
+                .map(|color| (color.r, color.g, color.b, color.weight))
+                .collect();
         return Ok(GeneratedThumbnail {
             path: out_path,
             width: original_dimensions.0,
             height: original_dimensions.1,
+            palette,
         });
     }
 

src/components/ColorFilter.tsx

@@ -0,0 +1,158 @@
+import { useEffect, useRef, useState } from "react";
+import { AnimatePresence, motion } from "framer-motion";
+import { useGalleryStore } from "../store";
+import { Tooltip } from "./Tooltip";
+
+type Rgb = [number, number, number];
+
+// Representative colors for the quick-pick swatches. Each is just an RGB the
+// distance filter matches against — not a hard bucket.
+const SWATCHES: { name: string; rgb: Rgb }[] = [
+  { name: "Red", rgb: [226, 59, 59] },
+  { name: "Orange", rgb: [232, 134, 46] },
+  { name: "Yellow", rgb: [242, 207, 46] },
+  { name: "Green", rgb: [76, 175, 80] },
+  { name: "Teal", rgb: [31, 182, 166] },
+  { name: "Blue", rgb: [59, 125, 216] },
+  { name: "Purple", rgb: [139, 92, 246] },
+  { name: "Pink", rgb: [236, 72, 153] },
+  { name: "Brown", rgb: [139, 90, 43] },
+  { name: "Black", rgb: [26, 26, 26] },
+  { name: "White", rgb: [245, 245, 245] },
+  { name: "Gray", rgb: [154, 160, 166] },
+];
+
+function rgbEquals(a: Rgb | null, b: Rgb): boolean {
+  return a !== null && a[0] === b[0] && a[1] === b[1] && a[2] === b[2];
+}
+
+function toHex([r, g, b]: Rgb): string {
+  return `#${[r, g, b].map((n) => n.toString(16).padStart(2, "0")).join("")}`;
+}
+
+function fromHex(hex: string): Rgb {
+  const n = parseInt(hex.slice(1), 16);
+  return [(n >> 16) & 255, (n >> 8) & 255, n & 255];
+}
+
+export function ColorFilter() {
+  const colorFilter = useGalleryStore((state) => state.colorFilter);
+  const setColorFilter = useGalleryStore((state) => state.setColorFilter);
+  const colorBackfill = useGalleryStore((state) => state.colorBackfill);
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  const isActive = colorFilter !== null;
+  const isCustom = isActive && !SWATCHES.some((swatch) => rgbEquals(colorFilter, swatch.rgb));
+
+  // Collapse the panel when clicking elsewhere.
+  useEffect(() => {
+    if (!open) return;
+    const onPointerDown = (event: PointerEvent) => {
+      if (ref.current && !ref.current.contains(event.target as Node)) setOpen(false);
+    };
+    window.addEventListener("pointerdown", onPointerDown);
+    return () => window.removeEventListener("pointerdown", onPointerDown);
+  }, [open]);
+
+  return (
+    <div ref={ref} className="ml-1 flex items-center border-l border-white/[0.06] pl-2">
+      {/* Trigger — a single palette icon; shows the active color as a dot when a
+          filter is applied so the collapsed state still communicates it. */}
+      <Tooltip label={isActive ? "Color filter active" : "Filter by color"} delay={400}>
+        <button
+          className={`relative flex items-center gap-1.5 rounded-lg px-2 py-1.5 transition-colors ${
+            open || isActive ? "bg-white/10 text-white" : "text-gray-500 hover:bg-white/5 hover:text-gray-200"
+          }`}
+          onClick={() => setOpen((value) => !value)}
+          aria-label="Filter by color"
+        >
+          <svg className="h-3.5 w-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.6}
+              d="M12 3a9 9 0 100 18c.83 0 1.5-.67 1.5-1.5 0-.39-.15-.74-.39-1.01-.23-.26-.39-.61-.39-1 0-.83.67-1.5 1.5-1.5H16a5 5 0 005-5c0-4.42-4.03-8-9-8z" />
+            <circle cx="7.5" cy="11.5" r="1" fill="currentColor" stroke="none" />
+            <circle cx="11.5" cy="7.5" r="1" fill="currentColor" stroke="none" />
+            <circle cx="15.5" cy="9.5" r="1" fill="currentColor" stroke="none" />
+          </svg>
+          {isActive ? (
+            <span
+              className="h-3 w-3 rounded-full border border-white/30"
+              style={{ backgroundColor: toHex(colorFilter as Rgb) }}
+            />
+          ) : null}
+        </button>
+      </Tooltip>
+
+      <AnimatePresence initial={false}>
+        {open ? (
+          <motion.div
+            initial={{ width: 0, opacity: 0 }}
+            animate={{ width: "auto", opacity: 1 }}
+            exit={{ width: 0, opacity: 0 }}
+            transition={{ duration: 0.18, ease: "easeOut" }}
+            // Horizontal/vertical padding gives the active swatch's ring + scale
+            // room inside the overflow-hidden clip box (needed for the width slide).
+            // py-1 keeps the panel shorter than the always-present filter pills so
+            // opening it never changes the row height (no 1px toolbar shift).
+            className="flex items-center gap-1 overflow-hidden whitespace-nowrap px-1.5 py-1"
+          >
+            {SWATCHES.map((swatch) => {
+              const active = rgbEquals(colorFilter, swatch.rgb);
+              return (
+                <button
+                  key={swatch.name}
+                  title={swatch.name}
+                  aria-label={`Filter by ${swatch.name}`}
+                  className={`h-4 w-4 shrink-0 rounded-full border transition-transform ${
+                    active ? "scale-110 border-white/40 ring-2 ring-white/70" : "border-white/15 hover:scale-110"
+                  }`}
+                  style={{ backgroundColor: toHex(swatch.rgb) }}
+                  onClick={() => setColorFilter(active ? null : swatch.rgb)}
+                />
+              );
+            })}
+
+            {/* Custom color picker — rainbow until a custom color is chosen. */}
+            <label
+              title="Custom color"
+              className={`relative h-4 w-4 shrink-0 cursor-pointer overflow-hidden rounded-full border ${
+                isCustom ? "border-white/40 ring-2 ring-white/70" : "border-white/15 hover:scale-110"
+              }`}
+              style={
+                isCustom
+                  ? { backgroundColor: toHex(colorFilter as Rgb) }
+                  : { background: "conic-gradient(red, orange, yellow, lime, cyan, blue, magenta, red)" }
+              }
+            >
+              <input
+                type="color"
+                className="absolute inset-0 cursor-pointer opacity-0"
+                value={colorFilter ? toHex(colorFilter) : "#3b7dd8"}
+                onChange={(event) => setColorFilter(fromHex(event.target.value))}
+              />
+            </label>
+
+            {isActive ? (
+              <button
+                className="ml-0.5 shrink-0 rounded px-1 text-[11px] text-gray-500 transition-colors hover:text-gray-200"
+                onClick={() => setColorFilter(null)}
+                title="Clear color filter"
+              >
+                Clear
+              </button>
+            ) : null}
+
+            {colorBackfill && colorBackfill.total > 0 ? (
+              <span
+                className="ml-0.5 shrink-0 text-[10px] text-gray-600"
+                title="Sampling colors from existing thumbnails — color search fills in as this runs"
+              >
+                sampling {colorBackfill.processed.toLocaleString()}/{colorBackfill.total.toLocaleString()}
+              </span>
+            ) : null}
+          </motion.div>
+        ) : null}
+      </AnimatePresence>
+    </div>
+  );
+}

src/components/Gallery.tsx

@@ -3,6 +3,7 @@ import { useVirtualizer } from "@tanstack/react-virtual";
 import { convertFileSrc } from "@tauri-apps/api/core";
 import { ImageRecord, parseSearchValue, tileSizeForZoom, useGalleryStore } from "../store";
 import { BulkActionBar } from "./BulkActionBar";
+import { Tooltip } from "./Tooltip";
 
 const GAP = 6;
 
@@ -125,6 +126,7 @@ export function ImageTile({
   const src = image.thumbnail_path ? convertFileSrc(image.thumbnail_path) : null;
 
   return (
+    <Tooltip label={image.filename} delay={500} block followCursor>
     <button
       className={`media-dark-surface group relative overflow-hidden rounded-xl bg-white/[0.04] text-left focus:outline-none transition-shadow ${
         selected ? "ring-2 ring-inset ring-blue-400/80" : ""
@@ -141,7 +143,6 @@ export function ImageTile({
         onClick();
       }}
       onContextMenu={onContextMenu}
-      title={image.filename}
     >
       {/* Selection corner — a top-left zone that reveals the checkbox only when
           hovered (not the whole tile) and toggles selection on click. The
@@ -281,6 +282,7 @@ export function ImageTile({
         </div>
       </div>
     </button>
+    </Tooltip>
   );
 }
 

src/components/TitleBar.tsx

@@ -2,6 +2,7 @@ import { useState, useEffect } from "react";
 import { getCurrentWindow } from "@tauri-apps/api/window";
 import { useGalleryStore } from "../store";
 import { PhokusMark } from "./PhokusMark";
+import { Tooltip } from "./Tooltip";
 
 // SVG icons for window controls
 function MinimizeIcon() {
@@ -79,10 +80,9 @@ export function TitleBar() {
           up its focal point and the chip becomes a button that re-opens the prompt. */}
       <div className="flex items-center gap-2 pl-3 pr-4">
         {updatePending ? (
-          <div
-            className="group relative"
-            style={{ WebkitAppRegion: "no-drag" } as React.CSSProperties}
-          >
+          <div style={{ WebkitAppRegion: "no-drag" } as React.CSSProperties}>
+            {/* Instant tooltip (delay 0) — this affordance should read immediately. */}
+            <Tooltip label={`Click to update — v${updateVersion}`} delay={0} align="start">
               <button
                 onClick={() => void installUpdate()}
                 aria-label={`Update available — click to update to Phokus v${updateVersion}`}
@@ -91,10 +91,7 @@ export function TitleBar() {
                 <span className="pointer-events-none absolute left-1/2 top-1/2 h-3 w-3 -translate-x-1/2 -translate-y-1/2 rounded-full bg-amber-400/60 animate-ping" />
                 <PhokusMark className="relative h-4 w-4" dotClassName="fill-amber-400" />
               </button>
-            {/* Custom tooltip — fades in ~100ms instead of the native ~500ms delay. */}
-            <span className="pointer-events-none absolute left-0 top-full z-50 mt-1.5 whitespace-nowrap rounded-md border border-white/10 bg-gray-800 px-2 py-1 text-[11px] text-gray-200 opacity-0 shadow-lg transition-opacity duration-100 group-hover:opacity-100">
-              Click to update — v{updateVersion}
-            </span>
+            </Tooltip>
           </div>
         ) : (
           <div className="flex h-5 w-5 items-center justify-center rounded-md bg-white/8 overflow-hidden text-gray-300">

src/components/Toolbar.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef, useState } from "react";
 import { invoke } from "@tauri-apps/api/core";
 import { tileSizeForZoom, useGalleryStore, SortOrder, MediaFilter, SearchCommand, parseSearchValue, searchModeLabel, ExploreTagEntry } from "../store";
 import { FolderScopeDropdown } from "./FolderScopeDropdown";
+import { ColorFilter } from "./ColorFilter";
 
 const BASE_SORT_OPTIONS: { value: SortOrder; label: string }[] = [
   { value: "date_desc", label: "Newest first" },
@@ -478,6 +479,7 @@ export function Toolbar() {
             onClick={() => setFailedTaggingOnly(!failedTaggingOnly)}
           />
         ) : null}
+        <ColorFilter />
         {isSimilarResults ? <span className="ml-2 text-[11px] text-gray-500">Current similar scope: {similarScope === "current_album" ? "this album" : similarScope === "current_folder" ? "current folder" : "all media"}</span> : null}
       </div>
     </div>

src/components/Tooltip.tsx

@@ -0,0 +1,141 @@
+import { MouseEvent, ReactNode, useEffect, useRef, useState } from "react";
+import { motion } from "framer-motion";
+
+type TooltipSide = "top" | "bottom" | "left" | "right";
+type TooltipAlign = "center" | "start" | "end";
+
+// Horizontal alignment only applies to top/bottom; left/right center vertically.
+function positionClasses(side: TooltipSide, align: TooltipAlign): string {
+  if (side === "left") return "right-full top-1/2 mr-1.5 -translate-y-1/2";
+  if (side === "right") return "left-full top-1/2 ml-1.5 -translate-y-1/2";
+  const vertical = side === "top" ? "bottom-full mb-1.5" : "top-full mt-1.5";
+  const horizontal = align === "start" ? "left-0" : align === "end" ? "right-0" : "left-1/2 -translate-x-1/2";
+  return `${vertical} ${horizontal}`;
+}
+
+const BASE_CLASSES =
+  "pointer-events-none z-50 whitespace-nowrap rounded-md border border-white/10 bg-gray-800 px-2 py-1 text-[11px] text-gray-200 shadow-lg";
+const STATIC_CLASSES = `${BASE_CLASSES} transition-opacity duration-100`;
+
+/**
+ * Lightweight custom tooltip — fades in (faster than the native one) after a
+ * tunable hover `delay`, and hides instantly on leave or click. By default it
+ * anchors to a `side` of the wrapper; with `followCursor` it tracks the pointer
+ * (fixed-positioned, so it escapes scroll-container clipping).
+ */
+export function Tooltip({
+  label,
+  delay = 400,
+  side = "bottom",
+  align = "center",
+  block = false,
+  followCursor = false,
+  className = "",
+  children,
+}: {
+  label: ReactNode;
+  /** Milliseconds the pointer must hover before the tooltip appears (0 = instant). */
+  delay?: number;
+  side?: TooltipSide;
+  /** Horizontal alignment for top/bottom tooltips. */
+  align?: TooltipAlign;
+  /** Full-width block wrapper (e.g. wrapping a grid cell) instead of inline. */
+  block?: boolean;
+  /** Track the cursor (fixed position) instead of anchoring to a side. */
+  followCursor?: boolean;
+  /** Extra classes for the wrapper (e.g. layout). */
+  className?: string;
+  children: ReactNode;
+}) {
+  const [visible, setVisible] = useState(false);
+  const [coords, setCoords] = useState({ x: 0, y: 0 });
+  const timer = useRef<ReturnType<typeof setTimeout> | undefined>(undefined);
+  const frame = useRef<number | undefined>(undefined);
+  const tooltipRef = useRef<HTMLSpanElement>(null);
+
+  // Resolve a viewport-safe position near the cursor: below-right by default,
+  // but flipped above the cursor if it would overflow the bottom edge, and
+  // clamped so it never runs off the right/left.
+  const place = (clientX: number, clientY: number) => {
+    const tip = tooltipRef.current;
+    const tipWidth = tip?.offsetWidth ?? 0;
+    const tipHeight = tip?.offsetHeight ?? 24;
+    const gap = 16;
+    let top = clientY + gap;
+    if (top + tipHeight > window.innerHeight - 4) {
+      top = clientY - gap - tipHeight;
+    }
+    let left = clientX + 14;
+    if (left + tipWidth > window.innerWidth - 4) left = window.innerWidth - 4 - tipWidth;
+    if (left < 4) left = 4;
+    setCoords({ x: left, y: top });
+  };
+
+  const clear = () => {
+    if (timer.current) clearTimeout(timer.current);
+    timer.current = undefined;
+    if (frame.current !== undefined) cancelAnimationFrame(frame.current);
+    frame.current = undefined;
+  };
+  const show = (event: MouseEvent<HTMLSpanElement>) => {
+    clear();
+    if (followCursor) place(event.clientX, event.clientY);
+    if (delay <= 0) {
+      setVisible(true);
+      return;
+    }
+    timer.current = setTimeout(() => setVisible(true), delay);
+  };
+  const hide = () => {
+    clear();
+    setVisible(false);
+  };
+  const move = (event: MouseEvent<HTMLSpanElement>) => {
+    if (!followCursor) return;
+    const { clientX, clientY } = event;
+    if (frame.current !== undefined) cancelAnimationFrame(frame.current);
+    frame.current = requestAnimationFrame(() => {
+      frame.current = undefined;
+      place(clientX, clientY);
+    });
+  };
+
+  useEffect(() => clear, []);
+
+  return (
+    <span
+      className={`${block ? "relative block w-full" : "relative inline-flex"} ${className}`}
+      onMouseEnter={show}
+      onMouseMove={followCursor ? move : undefined}
+      onMouseLeave={hide}
+      onPointerDown={hide}
+    >
+      {children}
+      {followCursor ? (
+        <motion.span
+          ref={tooltipRef}
+          role="tooltip"
+          // Fixed (so the scroll container's overflow doesn't clip it) and
+          // positioned by `place()` near the cursor with viewport-edge flipping.
+          className={`fixed ${BASE_CLASSES}`}
+          initial={false}
+          animate={{ left: coords.x, top: coords.y, opacity: visible ? 1 : 0 }}
+          transition={{
+            left: { type: "spring", stiffness: 700, damping: 45, mass: 0.35 },
+            top: { type: "spring", stiffness: 520, damping: 34, mass: 0.45 },
+            opacity: { duration: visible ? 0.1 : 0.05 },
+          }}
+        >
+          {label}
+        </motion.span>
+      ) : (
+        <span
+          role="tooltip"
+          className={`absolute ${STATIC_CLASSES} ${positionClasses(side, align)} ${visible ? "opacity-100" : "opacity-0"}`}
+        >
+          {label}
+        </span>
+      )}
+    </span>
+  );
+}

src/store.ts

@@ -354,6 +354,8 @@ interface GalleryState {
   minimumRating: number;
   failedEmbeddingsOnly: boolean;
   failedTaggingOnly: boolean;
+  colorFilter: [number, number, number] | null; // [r,g,b] dominant-color filter
+  colorBackfill: { processed: number; total: number; done: boolean } | null;
   zoomPreset: ZoomPreset;
   selectedImage: ImageRecord | null;
   collectionTitle: string | null;
@@ -469,6 +471,7 @@ interface GalleryState {
   setMinimumRating: (minimumRating: number) => void;
   setFailedEmbeddingsOnly: (failedEmbeddingsOnly: boolean) => void;
   setFailedTaggingOnly: (failedTaggingOnly: boolean) => void;
+  setColorFilter: (color: [number, number, number] | null) => void;
   showFailedTagging: (folderId: number) => void;
   setZoomPreset: (zoomPreset: ZoomPreset) => void;
   openImage: (image: ImageRecord) => void;
@@ -834,6 +837,8 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
   minimumRating: 0,
   failedEmbeddingsOnly: false,
   failedTaggingOnly: false,
+  colorFilter: null,
+  colorBackfill: null,
   zoomPreset: "comfortable",
   selectedImage: null,
   collectionTitle: null,
@@ -1062,7 +1067,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
   },
 
   loadImages: async (reset = false) => {
-    const { selectedFolderId, search, sort, loadedCount, mediaFilter, favoritesOnly, minimumRating, failedEmbeddingsOnly, failedTaggingOnly, activeView } = get();
+    const { selectedFolderId, search, sort, loadedCount, mediaFilter, favoritesOnly, minimumRating, failedEmbeddingsOnly, failedTaggingOnly, colorFilter, activeView } = get();
     const parsedSearch = parseSearchValue(search);
     const requestToken = ++galleryRequestToken;
     // Any fresh collection load invalidates a selection that referenced the
@@ -1176,6 +1181,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
           rating_min: minimumRating > 0 ? minimumRating : null,
           embedding_failed_only: failedEmbeddingsOnly,
           tagging_failed_only: failedTaggingOnly,
+          color: colorFilter,
           sort,
           offset,
           limit: activeView === "timeline" ? TIMELINE_PAGE_SIZE : PAGE_SIZE,
@@ -1317,6 +1323,11 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     void get().loadImages(true);
   },
 
+  setColorFilter: (colorFilter) => {
+    set({ colorFilter, images: [], loadedCount: 0, collectionTitle: null, similarSourceImageId: null, similarHasMore: false, imageLoadError: null });
+    void get().loadImages(true);
+  },
+
   showFailedTagging: (folderId) => {
     set({
       selectedFolderId: folderId,
@@ -2939,6 +2950,13 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       }
     });
 
+    const unlistenColorBackfill = await listen<{ processed: number; total: number; done: boolean }>(
+      "color-backfill-progress",
+      (event) => {
+        set({ colorBackfill: event.payload.done ? null : event.payload });
+      },
+    );
+
     return () => {
       unlistenProgress();
       unlistenMediaJobs();
@@ -2949,6 +2967,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       unlistenWatcherDeleted();
       unlistenFolderCounts();
       unlistenFfmpegProgress();
+      unlistenColorBackfill();
     };
   },
 }));