feat: added region color customization feature

src/core/commands/region/PasteRegionsCommand.ts

@@ -8,6 +8,7 @@ import { KGMidiPitchBend } from '../../midi/KGMidiPitchBend';
 import { KGTrack } from '../../track/KGTrack';
 import { generateUniqueId } from '../../../util/miscUtil';
 import { useProjectStore } from '../../../stores/projectStore';
+import { KGAudioRegion } from '../../region/KGAudioRegion';
 
 /**
  * Command to paste regions with their notes to a target track at a specific position
@@ -71,6 +72,7 @@ export class PasteRegionsCommand extends KGCommand {
           newPosition,
           originalRegion.getLength()
         );
+        newRegion.setColor(originalRegion.getColor());
         
         // Copy all notes from the original region
         const originalNotes = originalRegion.getNotes();
@@ -102,6 +104,22 @@ export class PasteRegionsCommand extends KGCommand {
         });
         
         console.log(`Created MIDI region "${newRegion.getName()}" with ${originalNotes.length} notes`);
+      } else if (originalRegion instanceof KGAudioRegion) {
+        newRegion = new KGAudioRegion(
+          generateUniqueId('KGAudioRegion'),
+          targetTrack.getId().toString(),
+          targetTrack.getTrackIndex(),
+          `${originalRegion.getName()} (Copy)`,
+          newPosition,
+          originalRegion.getLength(),
+          originalRegion.getAudioFileId(),
+          originalRegion.getAudioFileName(),
+          originalRegion.getAudioDurationSeconds(),
+          originalRegion.getClipStartOffsetSeconds()
+        );
+        newRegion.setColor(originalRegion.getColor());
+
+        console.log(`Created audio region "${newRegion.getName()}"`);
       } else {
         // Fallback for other region types
         newRegion = new KGRegion(
@@ -112,6 +130,7 @@ export class PasteRegionsCommand extends KGCommand {
           newPosition,
           originalRegion.getLength()
         );
+        newRegion.setColor(originalRegion.getColor());
         
         console.log(`Created region "${newRegion.getName()}"`);
       }

src/core/commands/region/SplitRegionCommand.ts

@@ -93,6 +93,8 @@ export class SplitRegionCommand extends KGCommand {
         this.splitAtBeat,
         regionLength - splitOffsetBeats
       );
+      region1.setColor(originalRegion.getColor());
+      region2.setColor(originalRegion.getColor());
 
       for (const note of originalRegion.getNotes()) {
         if (note.getStartBeat() < splitOffsetBeats) {
@@ -167,6 +169,7 @@ export class SplitRegionCommand extends KGCommand {
         originalRegion.getAudioDurationSeconds(),
         originalRegion.getClipStartOffsetSeconds()
       );
+      this.region1.setColor(originalRegion.getColor());
 
       this.region2 = new KGAudioRegion(
         generateUniqueId('KGAudioRegion'),
@@ -180,6 +183,7 @@ export class SplitRegionCommand extends KGCommand {
         originalRegion.getAudioDurationSeconds(),
         originalRegion.getClipStartOffsetSeconds() + splitOffsetSeconds
       );
+      this.region2.setColor(originalRegion.getColor());
 
     } else {
       throw new Error(`Unsupported region type for splitting: ${originalRegion.getCurrentType()}`);

src/core/commands/region/UpdateRegionCommand.test.ts

@@ -0,0 +1,54 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { KGCore } from '../../KGCore';
+import { KGProject } from '../../KGProject';
+import { KGTrack } from '../../track/KGTrack';
+import { KGMidiRegion } from '../../region/KGMidiRegion';
+import { UpdateRegionCommand } from './UpdateRegionCommand';
+
+vi.mock('../../KGCore', () => ({
+  KGCore: {
+    instance: vi.fn(),
+  },
+}));
+
+describe('UpdateRegionCommand', () => {
+  let track: KGTrack;
+  let region: KGMidiRegion;
+  let project: KGProject;
+  const mockCore = {
+    getCurrentProject: vi.fn(),
+  };
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    track = new KGTrack('Track 1', 1);
+    region = new KGMidiRegion('region-1', '1', 0, 'Verse', 0, 4);
+    track.setRegions([region]);
+    project = new KGProject('Test', 32, 0, 125, undefined, undefined, undefined, undefined, undefined, 1, [track], 11);
+    mockCore.getCurrentProject.mockReturnValue(project);
+    vi.mocked(KGCore.instance).mockReturnValue(mockCore as unknown as KGCore);
+  });
+
+  it('updates color and restores it on undo', () => {
+    const command = new UpdateRegionCommand('region-1', { color: '#3D77C9' });
+
+    command.execute();
+
+    expect(region.getColor()).toBe('#3D77C9');
+    expect(command.getChangedProperties()).toEqual(new Set(['color']));
+
+    command.undo();
+
+    expect(region.getColor()).toBeUndefined();
+  });
+
+  it('clears an existing region color override', () => {
+    region.setColor('#B43F1D');
+    const command = new UpdateRegionCommand('region-1', { color: null });
+
+    command.execute();
+
+    expect(region.getColor()).toBeUndefined();
+    expect(command.getChangedProperties()).toEqual(new Set(['color']));
+  });
+});

src/core/commands/region/UpdateRegionCommand.ts

@@ -8,7 +8,7 @@ import { KGTrack } from '../../track/KGTrack';
  */
 export interface RegionUpdateProperties {
   name?: string;
-  // Future properties can be added here (e.g., color, instrument, etc.)
+  color?: string | null;
 }
 
 /**
@@ -58,6 +58,7 @@ export class UpdateRegionCommand extends KGCommand {
     // Store original properties for undo
     this.originalProperties = {
       name: this.targetRegion.getName(),
+      color: this.targetRegion.getColor(),
     };
 
     // Apply updates and track what actually changes
@@ -70,6 +71,12 @@ export class UpdateRegionCommand extends KGCommand {
       updatedProperties.push(`name: "${this.originalProperties.name}" → "${this.newProperties.name}"`);
     }
 
+    if ('color' in this.newProperties && this.newProperties.color !== this.originalProperties.color) {
+      this.targetRegion.setColor(this.newProperties.color ?? undefined);
+      this.changedProperties.add('color');
+      updatedProperties.push(`color: ${this.originalProperties.color ?? 'none'} → ${this.newProperties.color ?? 'none'}`);
+    }
+
     if (updatedProperties.length > 0) {
       console.log(`Updated region ${this.regionId}: ${updatedProperties.join(', ')}`);
     } else {
@@ -91,6 +98,11 @@ export class UpdateRegionCommand extends KGCommand {
       restoredProperties.push(`name: "${this.originalProperties.name}"`);
     }
 
+    if (this.changedProperties.has('color')) {
+      this.targetRegion.setColor(this.originalProperties.color ?? undefined);
+      restoredProperties.push(`color: ${this.originalProperties.color ?? 'none'}`);
+    }
+
     console.log(`Restored region ${this.regionId}: ${restoredProperties.join(', ')}`);
   }
 
@@ -101,6 +113,9 @@ export class UpdateRegionCommand extends KGCommand {
     if (this.newProperties.name !== undefined) {
       updatedProps.push('name');
     }
+    if ('color' in this.newProperties) {
+      updatedProps.push('color');
+    }
 
     if (updatedProps.length === 1) {
       return `Update region "${regionName}" ${updatedProps[0]}`;
@@ -152,4 +167,4 @@ export class UpdateRegionCommand extends KGCommand {
   public getChangedProperties(): Set<keyof RegionUpdateProperties> {
     return new Set(this.changedProperties);
   }
-}
+}

src/core/commands/track/UpdateTrackCommand.test.ts

@@ -84,4 +84,27 @@ describe('UpdateTrackCommand', () => {
     expect(mockAudioInterface.setTrackSolo).not.toHaveBeenCalled();
     expect(command.getChangedProperties()).toEqual(new Set());
   });
+
+  it('updates color and restores it on undo', () => {
+    const command = new UpdateTrackCommand(1, { color: '#3C8AC4' });
+
+    command.execute();
+
+    expect(track.getColor()).toBe('#3C8AC4');
+    expect(command.getChangedProperties()).toEqual(new Set(['color']));
+
+    command.undo();
+
+    expect(track.getColor()).toBeUndefined();
+  });
+
+  it('clears an existing color override', () => {
+    track.setColor('#B43F1D');
+    const command = new UpdateTrackCommand(1, { color: null });
+
+    command.execute();
+
+    expect(track.getColor()).toBeUndefined();
+    expect(command.getChangedProperties()).toEqual(new Set(['color']));
+  });
 });

src/core/commands/track/UpdateTrackCommand.ts

@@ -14,6 +14,7 @@ export interface TrackUpdateProperties {
   volume?: number;
   muted?: boolean;
   solo?: boolean;
+  color?: string | null;
 }
 
 /**
@@ -51,6 +52,7 @@ export class UpdateTrackCommand extends KGCommand {
       volume: this.targetTrack.getVolume(),
       muted: this.targetTrack.getMuted(),
       solo: this.targetTrack.getSolo(),
+      color: this.targetTrack.getColor(),
     };
 
     // Store original instrument if it's a MIDI track
@@ -133,6 +135,16 @@ export class UpdateTrackCommand extends KGCommand {
       updatedProperties.push(`solo: ${originalSolo} → ${newSolo}`);
     }
 
+    if ('color' in this.newProperties && this.newProperties.color !== this.originalProperties.color) {
+      const newColor = this.newProperties.color ?? undefined;
+      const originalColor = this.originalProperties.color;
+
+      this.targetTrack.setColor(newColor);
+
+      this.changedProperties.add('color');
+      updatedProperties.push(`color: ${originalColor ?? 'none'} → ${newColor}`);
+    }
+
     if (updatedProperties.length > 0) {
       console.log(`Updated track ${this.trackId}: ${updatedProperties.join(', ')}`);
     } else {
@@ -204,6 +216,11 @@ export class UpdateTrackCommand extends KGCommand {
       restoredProperties.push(`solo: ${this.originalProperties.solo}`);
     }
 
+    if (this.changedProperties.has('color')) {
+      this.targetTrack.setColor(this.originalProperties.color ?? undefined);
+      restoredProperties.push(`color: ${this.originalProperties.color ?? 'none'}`);
+    }
+
     console.log(`Restored track ${this.trackId}: ${restoredProperties.join(', ')}`);
   }
 
@@ -229,6 +246,9 @@ export class UpdateTrackCommand extends KGCommand {
     if (this.newProperties.solo !== undefined) {
       updatedProps.push('solo');
     }
+    if ('color' in this.newProperties) {
+      updatedProps.push('color');
+    }
 
     if (updatedProps.length === 1) {
       return `Update track "${trackName}" ${updatedProps[0]}`;