The first Android phone is only available in two colors, black and white, the white version of the phone has just recently been released so if you get bored of looking at black all day go over to your nearest T-Mobile store and get one. Now, if you want more colors to choose from then first you will still need to buy a black or white model and get it to a company called Colorware for options on personalizing your G1.
Colorware will for a cost of $150 add various different colors to your G1 to fit your needs. When finish you will be able to get it coated with a tough plastic coating called the X2 or something and that’s about it. This service is only available to citizens living in the US so all you other G1 owners are basically out of luck where coloring your G1 is concerned.
Note: If your phone has a warranty doing this will void all warranty most likely so if I were you I’d probably keep a safe distance.