feat: Add color column with filter to spool list

Add optional color column to spool list showing filament color swatches
with multi-select filtering capability.

Backend:
- GET /api/v1/color endpoint to list distinct filament colors
- filament.color_hex query param on spool list for filtering

Frontend:
- ColorFilterColumn component renders color swatches
- useSpoolmanColors() hook fetches available colors
- Filter dropdown shows swatches with hex codes
- Column hidden by default (enable via column selector)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

spoolman/api/v1/other.py

@@ -47,6 +47,33 @@ async def find_materials(
     return await filament.find_materials(db=db)
 
 
+@router.get(
+    "/color",
+    name="Find colors",
+    description="Get a list of all filament colors (hex codes).",
+    response_model_exclude_none=True,
+    responses={
+        200: {
+            "description": "A list of all filament color hex codes.",
+            "content": {
+                "application/json": {
+                    "example": [
+                        "FF0000",
+                        "00FF00",
+                        "0000FF",
+                    ],
+                },
+            },
+        },
+    },
+)
+async def find_colors(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> list[str]:
+    return await filament.find_colors(db=db)
+
+
 @router.get(
     "/article-number",
     name="Find article numbers",

spoolman/api/v1/spool.py

@@ -212,6 +212,17 @@ async def find(
             ),
         ),
     ] = None,
+    filament_color_hex: Annotated[
+        Optional[str],
+        Query(
+            alias="filament.color_hex",
+            title="Filament Color",
+            description=(
+                "Filter by exact filament color hex code (without #). Separate multiple colors with a comma."
+            ),
+            examples=["FF0000", "FF0000,00FF00,0000FF"],
+        ),
+    ] = None,
     filament_vendor_name: Annotated[
         Optional[str],
         Query(
@@ -321,6 +332,7 @@ async def find(
         filament_name=filament_name if filament_name is not None else filament_name_old,
         filament_id=filament_ids,
         filament_material=filament_material if filament_material is not None else filament_material_old,
+        filament_color_hex=filament_color_hex,
         vendor_name=filament_vendor_name if filament_vendor_name is not None else vendor_name_old,
         vendor_id=filament_vendor_ids,
         location=location,