/etc/X11/gpe-login.gtkrc is in gpe-login 0.95-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 | gtk-font-name = "Sans 8"
include "/usr/share/themes/Angelistic/gtk-2.0/gtkrc"
style "default"
{
bg[NORMAL] = "#90d8ff"
}
widget "*" style "default"
|