Replace panel tileKey with a direct color prop.

Drop theme panelTiles keys and the ArticleView update callback wiring.

src/components/article/boxes/ArticleViewPrice.jsx

@@ -506,6 +506,7 @@ export default class ArticleViewPrice extends Component {
       <EditablePanelTile
         wide={1}
         minHeight={SECOND_ROW_MIN_HEIGHT}
+        color="#bfdbfe"
         contentAlignItems="flex-start"
         value={priceValue}
         onSave={this.handleSave}