How hot does it get in Colorado?

Depends on summer or winter.
Summer we hit 80s-90s on the eastern plains, and sometimes the rare 100 (on a dry summer). And sometimes summer starts later and we can have 50s and 60s in June (and it has gotten cooler then that too)

It's a tad cooler in the mountains with the shade of the forests and the elevation.
Sometimes depending on where the jet stream is we can get wind storms lasting weeks that reach about 45-75mph (that's not gusts) and that cools things down a bit. *many people are surprised we have such strong winds in such a mountainous state, but we do*
anyways for the winter we can have 70s for the winter when the sun is out and we don't have a low pressure system over us. Yet we can also have some winter days where we reach a high of 14 in the day time. Last winter we had a three week run of the temperature only reaching about 10 where I live.

Main rule is winter cold, cool, and sometimes hot; summer hot, hotter, sometimes cool
the further east you go the better chances of higher temps, the further west the cool it gets. Yet it doesn't always follow that way because the mountains direct how our weather is.