User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:2.0) Gecko/20110321 Firefox/4.0 Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0) Gecko/20110321 Firefox/4.0 I use a dark color scheme on my system to be nice to my eyes. When I open a new tab in Firefox 4.0 the background of the new tab flashes white for a moment and only changes to the correct darker background color when the content of the new tab starts rendering. I already tried to set browser.display.background_color to a dark value and disabled browser.display.use_system_colors as was told in the description of browser.display.background_color but it did not solve the problem. Reproducible: Always Steps to Reproduce: 0. Make sure you have set a dark background color. 1. Open Firefox 4.0. 2. Make sure all tabs are closed except one. 3. Open a new tab by clicking the little + sign. Actual Results: The background of the newly opened tab flashes white for a moment and then changes to the configured dark background color. Expected Results: The background of the new tab should be rendered in the configured dark color from the very beginning.

Similar to bug 644874?

I confirm this behaviour, and that its very irritating. Its VERY evident when using vimperator/pentadactyl, since new tabs are opened in the foreground by default. Also very evident on slower internet speeds (high-latency parts of the world). This did not occur in firefox 3.x

Confirmed on Mozilla/5.0 (Windows NT 6.1; rv:2.2a1pre) Gecko/20110329 Firefox/4.2a1pre Clicking on a new tab button, there is a white flash in the background for a moment and then it opens the tabs as per the background colour.

Could you try and find the regression range if possible, please: http://harthur.github.com/mozregression/