Agree with Adi, orange! Mutant bright red blood can't pop up everywhere. (Oh hey, maybe it could be mutant GRAY blood or even WHITE, too. That'd be fun. XD) Also, orange. Totes orange. And massive typical-rustblood psychic powers that he can't contain/use with any grace at first. That parallels Kyuubi pretty well.

I think Sasuke would be dark blue. Not sure which shade though. Hm. And yes, agree on Sakura being green. Probably spring-leaf-green. N'aww. Wonder where Kakashi would be at, though.