While the Game Boy Micro system is relatively new, there’s already a bunch of different designs for it. Japan launched with four different colors: black, blue, silver and purple. Europe had also came out with four colors except they got pink and green instead of purple and black. An interesting note is that only the US Micro package came packaged with extra faceplates like the cool looking Ammonite design.
See all of the released Micros including four limited edition systems here.