Update app.py

app.py

@@ -446,7 +446,7 @@ def draw_mask(o, b, v, d, evt: gr.EventData):
     mask = np.where((mask==2)|(mask==0),0,1).astype('uint8')
 
     frame = cv2.imread(frames[frame_selected], cv2.IMREAD_UNCHANGED).astype(np.uint8)
-    frame[mask>0] = (255,255,255)
+    frame[mask>0] = (0,0,0,0)
     cv2.imwrite(frames[frame_selected], frame)
     
     switch_rows(False)