All ETBs are green - some may have white on them or even some high amounts of black, but generally green.
ATBs are all different colors - except green. haha A lot of people would love a green ATB, but the closest I've seen are greenish-grey. I think a few keepers are working on pairing together greenish ATBs to try and produce geen Ammies.
The ETB Mike has posted is a typical example and very beautiful. They start off as red neonates usually.