On one hand you have a chance to save yourself $200+ for a year and probably be A-Okay.
On the other hand you have a chance of getting a traffic citation, getting into an accident or something that could net you a fine likely exceeding that amount if you get caught. Depending on how "up to speed" the local government is, they may hunt you down if you do something such as file taxes, change your voting registration to the new area, get a parking pass somewhere, etc.
Do insurance costs in CO offset the registration costs or anything? You could possibly save yourself more money overall if you registered in CO then switched your insurance. Are you moving in to a permanent situation? Do your parents still live in the state you are leaving so you could claim their house as your "permanent address"? Overall, I'd go with registering in your old state and just keep one eye open.