diff --git a/frontend/app/block/block.less b/frontend/app/block/block.less
index 00445f572..ee6e6fb1d 100644
--- a/frontend/app/block/block.less
+++ b/frontend/app/block/block.less
@@ -54,6 +54,10 @@
         }
     }
 
+    &.block-preview.block-frame-default .block-frame-default-inner .block-frame-default-header {
+        background-color: rgba(0, 0, 0, 0.7);
+    }
+
     &.block-frame-default {
         position: relative;
         padding: 2px;
diff --git a/frontend/app/block/block.tsx b/frontend/app/block/block.tsx
index 0c67f13aa..b5e931773 100644
--- a/frontend/app/block/block.tsx
+++ b/frontend/app/block/block.tsx
@@ -383,7 +383,7 @@ const BlockFrame_Default_Component = ({
     }
 
     const innerStyle: React.CSSProperties = {};
-    if (customBg?.bg != null) {
+    if (!preview && customBg?.bg != null) {
         innerStyle.background = customBg.bg;
         if (customBg["bg:opacity"] != null) {
             innerStyle.opacity = customBg["bg:opacity"];