ao2.it
Antonio Ospite, theorist attacks

Most Gtk+ themes offer a “light” and a “dark” variant, however I found out that these names are just conventional: a Gtk+ theme can define variants with arbitrary names, so maybe this can be used for some fun stuff.

I set up a proof of concept: I defined a “red” variant and used it to restyle windows when the user is operating as root, Timm Bäder told me that someone from Elementary OS has come up with this idea already but I didn't find a practical demonstration, so here it is:

The code to set the variant when the root shell is executed can be found in the patch from GNOME Bug 769194.