Possible to change white iframe flash when navigating away from a web player page?

First, a clarification of the issue. If you load any Unity web player page, and then tell your browser to go to a different page, you’ll see the Unity iframe flash white for a brief moment.

I’m wondering if there’s any way of changing this to black. It doesn’t seem to be affected by any of the background colour settings in the HTML file, or any in-game settings.

No it’s not. It’s the content of the browser’s “about:blank” file which is native to the browser.

HOWEVER, if the IFrame has an ID tag, you could hide the iframe entirely.

window.onunload=function(){document.getElementById('theIdHere').style.display='none';};

You still might get a very brief flash of unstyled content, but it’ll be the shortest it could possibly be.