Many Drupal users had reported that Colorbox has a white flashing background when loading iframe content before reverting to the default black. If you are facing the same issue in Colorbox in your Drupal site then read on to find out the solution.
The problem can often be traced to the default CSS files of the Colorbox module. Check with the CSS files of the Colorbox module and it should solve the issue for you
Hope that helps.
The easiest way to solve a Drupal issue is to hand it to the Drupal experts. We can provide a wide range of Drupal services to help you maintain and manage your Drupal websites. Get in touch with us to know more.