@b4n I suppose that if the _user_ has the css file then yeah, its reasonable to assume they intended it and know how to put Geany specific overrides in that.
But its confusing if the GUI selection works if there is no user GTK override and not in other cases.
Perhaps the GUI selection should be removed from Geany, after all we shouldn't actually make it easy for users to override the all powerful Gnome theme using a GUI, but should tell them to go create an arcane CSS like text file in their `~/.config`.