When you edit the location bar text on Mac, the location bar background goes from yellow to white, but the endcap graphics don't change, so the edge of the site button still has the yellow background. The changing background was accomplished by Dao in bug 398020, styling things like this (attachment 288852 [details] [diff] [review]): #urlbar[level="low"][pageproxystate="valid"] > .autocomplete-textbox-container, #urlbar[level="high"][pageproxystate="valid"] #autocomplete-security-wrapper, #urlbar[level="low"][pageproxystate="valid"] #autocomplete-security-wrapper, #urlbar[level="broken"][pageproxystate="valid"] #autocomplete-security-wrapper { pageproxystate on urlbar already watches for edits. We should probably tie identity feedback to the same thing. Nominating for blocking since it's ugly.