Created attachment 729074 [details] Screenshot of transparent button User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20130324 Firefox/22.0 Build ID: 20130324031024 Steps to reproduce: Press the back button. Using a 22.0a1 build from 2013-03-24 Actual results: One can see through the button (see screenshot). Expected results: There should be a solid color behind the button.
Which Android device is that?
Created attachment 729118 [details] Nightly (03/25) - Screenshot Ok I can reproduce too, this is an Alcatel One Touch Evo 7" Phablet, and reproducible holding down the back button.
Created attachment 729647 [details] [diff] [review] Patch This uses the same approach as the tabs button. The combined colors are specified for normal and private modes. They are added to the LWTheme state list too.