I use Ubuntu 12.04 with the Blackbox window manager and the default (gray) GTK theme. With some GTK 3 applications, like Gedit, Disk utility and Evince I see black areas which should be gray and these black backgrounds make the black text on top of them impossible to read.
In Gedit all tabs turn black if I open a new tab after having launched the application. In Disk Utility all information is unreadable due to the black background in the right part of the window. In Evince the top of the side pane is black.
I tried the IceWM window manager but the black areas showed up there as well so I conclude that the problem is unrelated to the window manager.
It seems to me that very few people use the default theme as this bug (or bugs) has still not been fixed. Is anyone else experiencing this problem?
Here are my GTK settings:
$ cat ~/.config/gtk-3.0/settings.ini
[Settings]
gtk-theme-name = Default
gtk-icon-theme-name = hicolor
Update: After switching to Lubuntu 12.04 (still using Blackbox WM) I don't have this problem anymore. Don't ask me why.