I've done a bunch of cast and blast trips in my red NRS 15'. Sometimes I carry a couple of camo tarps to cover the whole setup if I plan to sit still. But I've found the best way to hunt ducks is either like Yac1 said or to float up to the upstream side of an island or bend and hop out and sneak up on whatever is sitting in the eddy below. A dog can be helpful if your ducks drop on the bank.
I'm pretty sure color doesnt matter to a deer or elk but I have noticed they spook quicker from a canoe than they do from a raft. I'd say it's probably more important to break up the outline of your body and conceal your face from big game.
"You're gonna be doin a lot of doobie rolling when youre LIVIN IN A VAN DOWN BY THE RIVER"