My specs; Slackware 14.1 x86_64 gtk+3-3.8.2 qt-4.8.5 qt5-5.3.2 TBB 4.0 Linux x64 I don't remember if TBB is compiled against GTK or QT? All of TBB doesn't show any themeing, from the startup window(s) to the browser itself. I'm attaching a screen shot you can see showing no theming, just like the browser... **Trac**: **Username**: torrified