I'm also looking for Trackdays in Colorado. For racetracks I've found:
High plains, pueblo, and pikes peak. They are the tracks that are on the racing league's calendar (MRA-racing.org)
I haven't found any track day organizations yet. However, I did find that High Plains Raceway sets up its own 'motorcycle lapping day' one or two Fridays per month.
That's not a lot of seat time. The additional track time could come from joining the MRA and participating in the formal races.
I'm going to go watch the MRA races at High Plains in early August, to ask the racers what Trackdays they use to practice. I'm sure they'll add some good info.
Thats what i was coming across.. These places dont have trackdays like here in illinois where you are able to go to a few different tracks within the area and through multiple vendors.. Hopefully things will change soon and more organizations will getting involved out there. Otherwise let me know what you find out from the racers at high plains!