I think Gaston had it right the first time. Other than the minor changes made to the frame e.g. 1st gen, 2nd gen, 3rd gen, I don't think anything needs to be done to change their appearance. I think most people buy Glock pistols because of their reliability, and quality, and not their appearance. If you are concerned with appearance, go out and buy one of them nickel plated sissy pistols.