Hey.
Having trudged through some major installation problems (http://www.ubuntuforums.org/showthread.php?t=8050), I just got Ubuntu working on a blue/white G3. It has a Rage 128, and the installer (or something) set XFree to work in 24-bit color.
That's all fine and good until console switching happens (i.e. to use MOL), in which case the X display gets horribly garbled. Switching to 16-bit color solves this problem entirely.