Horrible dark look of GTK+ 3 applications

After I used “Theme switcher” plugin for Quodlibet (audio player) and checked prefer dark theme version checkbox all GTK+ 3 applications except Quodlibet acquired such monstrous appearance as on the screen shot:http://www.zimagez.com/miniature/screenshot-121114-003650.php](http://www.zimagez.com/zimage/screenshot-121114-003650.php)

Disabling prefer dark theme version checkbox does not helped. Setting gtk-application-prefer-dark-theme option in ~/.config/gtk-3.0/settings.ini file to false does not help. If I disable that Quodlibet plugin Quodlibet also becomes dark and ugly.

The “Theme Switcher” plugin doesn’t change any system wide settings and doesn’t change any files, so this shouldn’t be the cause.

Maybe a gtk update broke it, there are some bugs causing black drawing in 3.14.5.

Can`t find how to fix this. What should I do?