Fix #129749: Use consistent GPv3 color settings in different modes

Always use the Brush.color setting in the Draw mode side bar.
Technically the "Color" panel in the sidebar can draw in other modes,
but it's polling for explicit tools that limit it to the Draw mode
implicitly.

Use the appropriate brush or unified color in other GP modes based on
the unified paint settings flag.

Worth noting this was technically broken for a long time:
The default was that unified paint is disabled, so the GP panels would
use the brush color as expected. Enabling unified paint would then break
the colors, probably wasn't done very frequently since GP files
and e.g. mesh sculpting don't mix often. The default was changed in
#129127 to enable unified paint by default, which now breaks GP colors
by default.

Pull Request: https://projects.blender.org/blender/blender/pulls/129790

scripts/startup/bl_ui/properties_grease_pencil_common.py

@@ -499,44 +499,6 @@ class GreasePencilMaterialsPanel:
             row.template_ID(space, "pin_id")
 
 
-class GreasePencilVertexcolorPanel:
-
-    def draw(self, context):
-        layout = self.layout
-        layout.use_property_split = True
-        layout.use_property_decorate = False
-
-        tool_settings = context.scene.tool_settings
-        is_vertex = context.mode == 'VERTEX_GPENCIL'
-        gpencil_paint = tool_settings.gpencil_vertex_paint if is_vertex else tool_settings.gpencil_paint
-        brush = gpencil_paint.brush
-        gp_settings = brush.gpencil_settings
-        tool = brush.gpencil_vertex_tool if is_vertex else brush.gpencil_tool
-
-        ob = context.object
-
-        if ob:
-            col = layout.column()
-            col.template_color_picker(brush, "color", value_slider=True)
-
-            sub_row = layout.row(align=True)
-            sub_row.prop(brush, "color", text="")
-            sub_row.prop(brush, "secondary_color", text="")
-
-            sub_row.operator("gpencil.tint_flip", icon='FILE_REFRESH', text="")
-
-            row = layout.row(align=True)
-            row.template_ID(gpencil_paint, "palette", new="palette.new")
-            if gpencil_paint.palette:
-                layout.template_palette(gpencil_paint, "palette", color=True)
-
-            if tool in {'DRAW', 'FILL'} and is_vertex is False:
-                row = layout.row(align=True)
-                row.prop(gp_settings, "vertex_mode", text="Mode")
-                row = layout.row(align=True)
-                row.prop(gp_settings, "vertex_color_factor", slider=True, text="Mix Factor")
-
-
 class GPENCIL_UL_layer(UIList):
     def draw_item(self, _context, layout, _data, item, icon, _active_data, _active_propname, _index):
         # assert(isinstance(item, bpy.types.GPencilLayer)

scripts/startup/bl_ui/space_view3d.py

@@ -20,7 +20,6 @@ from bl_ui.properties_grease_pencil_common import (
     AnnotationDataPanel,
     AnnotationOnionSkin,
     GreasePencilMaterialsPanel,
-    GreasePencilVertexcolorPanel,
 )
 from bl_ui.space_toolsystem_common import (
     ToolActivePanelHelper,
@@ -8594,17 +8593,22 @@ class TOPBAR_PT_grease_pencil_vertex_color(Panel):
             paint = context.scene.tool_settings.gpencil_paint
         elif ob.mode == 'VERTEX_GREASE_PENCIL':
             paint = context.scene.tool_settings.gpencil_vertex_paint
+        use_unified_paint = (ob.mode != 'PAINT_GREASE_PENCIL')
 
         ups = context.tool_settings.unified_paint_settings
         brush = paint.brush
-        prop_owner = ups if ups.use_unified_color else brush
+        prop_owner = ups if use_unified_paint and ups.use_unified_color else brush
 
         col = layout.column()
         col.template_color_picker(prop_owner, "color", value_slider=True)
 
         sub_row = layout.row(align=True)
-        UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "color", text="")
-        UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "secondary_color", text="")
+        if use_unified_paint:
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "color", text="")
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "secondary_color", text="")
+        else:
+            sub_row.prop(brush, "color", text="")
+            sub_row.prop(brush, "secondary_color", text="")
 
         sub_row.operator("paint.brush_colors_flip", icon='FILE_REFRESH', text="")
 

scripts/startup/bl_ui/space_view3d_toolbar.py

@@ -2159,16 +2159,25 @@ class VIEW3D_PT_tools_grease_pencil_brush_vertex_color(View3DPanel, Panel):
         tool_settings = context.tool_settings
         settings = tool_settings.gpencil_vertex_paint
         brush = settings.brush
+        use_unified_paint = (context.object.mode != 'PAINT_GREASE_PENCIL')
+        ups = context.tool_settings.unified_paint_settings
+        prop_owner = ups if use_unified_paint and ups.use_unified_color else brush
 
         col = layout.column()
 
-        col.template_color_picker(brush, "color", value_slider=True)
+        col.template_color_picker(prop_owner, "color", value_slider=True)
 
         sub_row = col.row(align=True)
-        sub_row.prop(brush, "color", text="")
-        sub_row.prop(brush, "secondary_color", text="")
+        if use_unified_paint:
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "color", text="")
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "secondary_color", text="")
+        else:
+            sub_row.prop(brush, "color", text="")
+            sub_row.prop(brush, "secondary_color", text="")
 
-        sub_row.operator("gpencil.tint_flip", icon='FILE_REFRESH', text="")
+        sub_row.operator("paint.brush_colors_flip", icon='FILE_REFRESH', text="")
+        if use_unified_paint:
+            sub_row.prop(ups, "use_unified_color", text="", icon='BRUSHES_ALL')
 
 
 class VIEW3D_PT_tools_grease_pencil_brush_vertex_falloff(GreasePencilBrushFalloff, Panel, View3DPaintPanel):
@@ -2272,7 +2281,7 @@ class VIEW3D_PT_tools_grease_pencil_brush_mixcolor(View3DPanel, Panel):
         sub_row.prop(brush, "color", text="")
         sub_row.prop(brush, "secondary_color", text="")
 
-        sub_row.operator("gpencil.tint_flip", icon='FILE_REFRESH', text="")
+        sub_row.operator("paint.brush_colors_flip", icon='FILE_REFRESH', text="")
 
         if brush.gpencil_tool in {'DRAW', 'FILL'}:
             col.prop(gp_settings, "vertex_mode", text="Mode")
@@ -2778,6 +2787,9 @@ class VIEW3D_PT_tools_grease_pencil_v3_brush_mixcolor(View3DPanel, Panel):
         settings = tool_settings.gpencil_paint
         brush = settings.brush
         gp_settings = brush.gpencil_settings
+        use_unified_paint = (context.object.mode != 'PAINT_GREASE_PENCIL')
+        ups = context.tool_settings.unified_paint_settings
+        prop_owner = ups if use_unified_paint and ups.use_unified_color else brush
 
         row = layout.row()
         row.prop(settings, "color_mode", expand=True)
@@ -2787,11 +2799,16 @@ class VIEW3D_PT_tools_grease_pencil_v3_brush_mixcolor(View3DPanel, Panel):
         col = layout.column()
         col.enabled = settings.color_mode == 'VERTEXCOLOR'
 
-        col.template_color_picker(brush, "color", value_slider=True)
+        # This panel is only used for Draw mode, which does not use unified paint settings.
+        col.template_color_picker(prop_owner, "color", value_slider=True)
 
         sub_row = col.row(align=True)
-        UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "color", text="")
-        UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "secondary_color", text="")
+        if use_unified_paint:
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "color", text="")
+            UnifiedPaintPanel.prop_unified_color(sub_row, context, brush, "secondary_color", text="")
+        else:
+            sub_row.prop(brush, "color", text="")
+            sub_row.prop(brush, "secondary_color", text="")
 
         sub_row.operator("paint.brush_colors_flip", icon='FILE_REFRESH', text="")