Customizing the look of the GDM / Login screen is a great way to add a personal touch to your system.

We do this by running the gnome-appearance-properties as the gdm user, and launch it through dbus-launch which sets up the appropriate environment variables for us. In short: fire up a terminal window and run:

gksudo -u gdm dbus-launch gnome-appearance-properties

You are asked to enter your password, after which you will be given an appearance dialog, but not just any appearance dialog: Changes here affects your GDM / Login screen, including background image, controls and colors.

Close the dialog when you’re done, and that’s all there is to it! Your next login will be prettified to your liking.