Help with Future Soldier Custom

[Purity]

So, I'm making this futuristic soldier. I sculpted everything( basically every piece of armor on a cheap dollar store wrestler). So I've given him a black wash and am trying to decide what colors to paint him. I just can't decide. I would like to have him have a black undersuit( similar to halo) but am game for anyhting if I like the sound of it. Think of a halo spartan mixed with a UNSC Marine. I'll post pics if you like.