Select Color: use the shared row gap in the RGB view too

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013rGmDUNr1hUf4zo1X3dak8

src/ui/color_select/editor.rs

@@ -270,7 +270,7 @@ impl ColorEditor {
                         byte(EditorMsg::Blue)
                     ),
                 ]
-                .spacing(10)
+                .spacing(ROW_GAP)
                 .into()
             }
             EditorMode::Field => {