Colorado In-State Tuition?

Hello all. I'm a young guy living in southern Maine, and am looking to move to Colorado soon and finish school there. My question is - how long do I have to live in Colorado before I can officially be eligible for In-state tuition? I heard 6 months somewhere, and 12 months somewhere else... just wondering, because I plan on going, whether it be a community college, or somewhere like Boulder or CU. I don't really care about cheating the system - just any way I can get in-state tuition in the shortest amount of time?