Hei all. I'm trying to edit a theme, in gtk 3, but I cannot fix the variable.

according to the docs, I need to use "GTK_THEME" variable. But that there's absolutely nowhere to be found. Any clues ?

PS: I've checked the docs here: https://wiki.archlinux.org/index.php/GTK%2B

For GTK+ 3, use the GTKTHEME environment variable, for example:<br>$ GTKTHEME=Adwaita:dark gnome-calculator
will launch GNOME Calculator with the dark variant of Adwaita theme.

Not working. Help ?