Customizing login theme (GDM)

Alright because I have dumped KDE4 and am now using Gnome I have GDM as my default login manager…
But it seems I cannot customize it, not from what I seen.
I like to change all aspects of my Linux user experience, the only thing I dont mess with is grub and the boot up theme.
But I do like to change my login theme, but so far I have not found out how to do this on opensuse.

I know what you meant when I was running Ubuntu or Fedora all the time it was easy to add a GDM login theme. OpenSUSE is probably the same way. I’m betting we just aren’t looking in the right place. I’m going to research this and see if I can change my login screen.