That's a McMurray Easter Egger, which they label an Ameracauna in their catalogue. I got several from them, and they were each slightly different at that age (because, mutts, you know) -- one was just like your chick. They are all feathering out a little differently now.
Probably a roo, of course.
My understanding is that if you breed an EE roo to your hens, the offspring will lay blue eggs if they hatched from white eggs, and green or olive eggs if they hatched from brown eggs. So that's something you could do in the future.