On Tue, Apr 19, 2016 at 07:19:07PM +0200, Tim Wiederhake wrote: > Installed gnome-themes-standard now (and rebooted, fwiw) to no effect. > > I hesitate to install gnome-tweak-tool, since I'm using xfce and > gnome-tweak-tool pulls in a lot of dependencies. Is there a cli way to > set the theme?
It's interesting that it happens under Xfce. I might have to make a fresh install in a virtual machine to try it. I think under Xfce you can change the theme through the applications menu > Settings > Appearance. What style do you have selected there? Does it work if you change it to Adwaita?

