Quote:OOPS ...not paying attention...sorry for the edit.
But then there is no line in the theme.css to import a gimp.css under the user's .config. Just from /etc which is root owned.
Will try adding this line to the theme.css if it doesn't get applied :
/.config/GIMP/3.0/gimp.css
It is very simple, make a three line gimp.css file. Put it in your Gimp User profile.
Linux: ~/.config/GIMP/3.0/
For Windows: C:\Users\"yourname"\AppData\Roaming\GIMP\3.0\