Allow Vue nodes to have their colors changed from selection toolbox (#5720)

## Summary

Fixes https://github.com/Comfy-Org/ComfyUI_frontend/issues/5680 by
allowing Vue nodes to properly synchronize color changes with LiteGraph
nodes, implementing header darkening and light theme adjustments.

<img width="2496" height="1512" alt="Screenshot from 2025-09-21
20-00-36"
src="https://github.com/user-attachments/assets/e3bdf645-1e0b-4d11-9ae5-9401f43e8e96"
/>

## Changes

- **What**: Implemented color property synchronization between LiteGraph
and Vue node rendering systems
- **Core Fix**: Added `nodeData.color` and `nodeData.bgcolor` to [v-memo
dependencies](https://vuejs.org/api/built-in-directives.html#v-memo) to
trigger re-renders on color changes
- **Color Logic**: Added header darkening using [memoized color
adjustments](https://github.com/Comfy-Org/ComfyUI_frontend/blob/main/src/utils/colorUtil.ts)
to match LiteGraph's ColorOption system
- **Event System**: Enhanced property change instrumentation in
LGraphNode.setColorOption to emit color/bgcolor events

## Review Focus

Vue component reactivity timing - the v-memo fix was critical for
immediate color updates. Verify light theme color adjustments match the
drawNode monkey patch behavior in app.ts.

## Technical Details

```mermaid
graph TD
    A[User Sets Color] --> B[LGraphNode.setColorOption]
    B --> C[Sets node.color & node.bgcolor]
    C --> D[Triggers property:changed events]
    D --> E[Vue Node Manager Updates]
    E --> F[v-memo Detects Change]
    F --> G[NodeHeader Re-renders]
    G --> H[Header Darkening Applied]

    style A fill:#f9f9f9,stroke:#333,color:#000
    style H fill:#f9f9f9,stroke:#333,color:#000
```

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5720-Allow-Vue-nodes-to-have-their-colors-changed-from-selection-toolbox-2766d73d36508123b441d126a74a54b2)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Myestery <Myestery@users.noreply.github.com>
Co-authored-by: DrJKL <DrJKL@users.noreply.github.com>
Co-authored-by: github-actions <github-actions@github.com>

src/renderer/extensions/vueNodes/components/LGraphNode.vue

@@ -34,7 +34,9 @@
     :style="[
       {
         transform: `translate(${position.x ?? 0}px, ${(position.y ?? 0) - LiteGraph.NODE_TITLE_HEIGHT}px)`,
-        zIndex: zIndex
+        zIndex: zIndex,
+        backgroundColor: nodeBodyBackgroundColor,
+        opacity: nodeOpacity
       },
       dragStyle
     ]"
@@ -47,9 +49,14 @@
         <SlotConnectionDot multi class="absolute left-0 -translate-x-1/2" />
         <SlotConnectionDot multi class="absolute right-0 translate-x-1/2" />
       </template>
-      <!-- Header only updates on title/color changes -->
       <NodeHeader
-        v-memo="[nodeData.title, isCollapsed, nodeData.flags?.pinned]"
+        v-memo="[
+          nodeData.title,
+          nodeData.color,
+          nodeData.bgcolor,
+          isCollapsed,
+          nodeData.flags?.pinned
+        ]"
         :node-data="nodeData"
         :readonly="readonly"
         :collapsed="isCollapsed"
@@ -139,6 +146,7 @@ import type { VueNodeData } from '@/composables/graph/useGraphNodeManager'
 import { toggleNodeOptions } from '@/composables/graph/useMoreOptionsMenu'
 import { useErrorHandling } from '@/composables/useErrorHandling'
 import { LiteGraph } from '@/lib/litegraph/src/litegraph'
+import { useSettingStore } from '@/platform/settings/settingStore'
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { useCanvasInteractions } from '@/renderer/core/canvas/useCanvasInteractions'
 import { TransformStateKey } from '@/renderer/core/layout/injectionKeys'
@@ -148,9 +156,11 @@ import { useVueElementTracking } from '@/renderer/extensions/vueNodes/composable
 import { useNodeExecutionState } from '@/renderer/extensions/vueNodes/execution/useNodeExecutionState'
 import { useNodeLayout } from '@/renderer/extensions/vueNodes/layout/useNodeLayout'
 import { useNodePreviewState } from '@/renderer/extensions/vueNodes/preview/useNodePreviewState'
+import { applyLightThemeColor } from '@/renderer/extensions/vueNodes/utils/nodeStyleUtils'
 import { app } from '@/scripts/app'
 import { useExecutionStore } from '@/stores/executionStore'
 import { useNodeOutputStore } from '@/stores/imagePreviewStore'
+import { useColorPaletteStore } from '@/stores/workspace/colorPaletteStore'
 import {
   getLocatorIdFromNodeData,
   getNodeByLocatorId
@@ -221,6 +231,23 @@ const hasAnyError = computed((): boolean => {
 const bypassed = computed((): boolean => nodeData.mode === 4)
 const muted = computed((): boolean => nodeData.mode === 2) // NEVER mode
 
+const nodeBodyBackgroundColor = computed(() => {
+  const colorPaletteStore = useColorPaletteStore()
+
+  if (!nodeData.bgcolor) {
+    return ''
+  }
+
+  return applyLightThemeColor(
+    nodeData.bgcolor,
+    Boolean(colorPaletteStore.completedActivePalette.light_theme)
+  )
+})
+
+const nodeOpacity = computed(
+  () => useSettingStore().get('Comfy.Node.Opacity') ?? 1
+)
+
 // Use canvas interactions for proper wheel event handling and pointer event capture control
 const { handleWheel, shouldHandleNodePointerEvents } = useCanvasInteractions()