I'd like to achieve something I thought would take a couple of seconds and turns out to be a nervous breakdown: override a theme's selected item color in a GTK3 theme.
At first, I naively though that overriding the value in ~/.config/gtk-3.0/gtk.css would to the trick, but no, it is ignored.
$ cat ~/.config/gtk-3.0/gtk.css
@define-color selected_bg_color #ff4e9a;
I then rsync'ed /usr/share/themes/<name> to ~/.themes and changed the wanted color in there by modifying the value of selected_bg_color, but that did nothing.
I sed'ed all the color values in the css file. Still ignored.
Finally, the only way I found to override one simple color was to "register" the local copied theme:
cd /home/foo/.themes/themename/gtk-3.0
glib-compile-resources gtk.gresource.xml
Is GTK3 so overengineered that there's no other way to override a color?
Edit: before anybody advise to launch gnome's Appearance menu, I'm running Mate Desktop, where preferences apply to GTK2.
Also gtk-theme-config does strictly nothing apart from filling ~/.config/gtk-3.0/gtk.css.