refactor:如果仪表板未设置底色，视图放大底色设置为白色

frontend/src/components/canvas/custom-component/UserViewDialog.vue

@@ -58,6 +58,9 @@ export default {
           }
         }
       }
+      if (!style.background) {
+        style.background = '#FFFFFF'
+      }
       return style
     },
     ...mapState([