When I was young and dumb, black for sure. Older and wiser, I'd pick the brightest color they have in an effort to be more visable to the caged zombies.
Do you have any experience on a bike? If you're taking the MSF class in May, just use one of the bikes provided and see how you do. 600's are great starter bikes for the right person. You don't have to use the higher rev's until you get more time in the seat and learn throttle control.