If you're in a tuxedo, that means you should be a in a bow tie, and it should be solid black. You should also tie it yourself (if you don't know how, let Alexander Olch show you the light). With self-tie bow ties, the knot you make is where you can express your individuality. It's not going to be perfect sure, but you can make it as messy or proper as you wish.
Band of Outsiders Solid Bow Tie
Buy It Now at Barneys $79
Brooks Brothers Butterfly Self-Tie Bow Tie
Buy It Now at Brooks Brothers, $60