Those are antenna's, lol. But I like how you made him all rainbow-ish. Typically he's just green and his outfit is, purple, I believe. His eyes are kinda of a dark pinkish-red with a white in it, to show the shine (no pupils or anything).
I just write poetry to throw my mean callous heartless exterior into sharp relief. I’m going to throw you off the ship anyway. — Vogon Captain (The Hitchhiker’s Guide to the Galaxy)