Pink fonts in GDM (sub-pixel antialiasing gone wrong?)

[mangobrain]

In GDM, and in some parts of GNOME (certain error messages, it seems), wherever text should be black, it is showing up pink. In GNOME itself, I've played around with the various colour orderings for sub-pixel antialiasing (whatever it's called - the one designed for TFT screens) and annoyingly NONE of them appear to work, the best I can get it down to is a slight reddish hue. So I've switched to normal ("best contrast" option) antialiasing, which is fine for when I'm logged in, but the option isn't applied at the login screen.

Is there any way to tell the GDM greeter what kind of antialiasing to use, and can anyone give any hints as to why none of the four colour orderings for subpixel antialiasing look right on my screen? Under the default, fonts are literally bright pink...