Are there any federal laws or laws in Colorado limiting reducing overtime hours? I work a fixed 50 hour week, so I receive 10 hours of overtime. My company wants to reduce my hours to 40. Are there any limitations to this? Can they reduce my pay if I took the job with the understanding that I would work 50 hours?

No, there is nothing illegal about cutting an employees hours of work. In some cases, you MIGHT get partial unemployment benefits, but I would think in your case, that won't happen.

However, there is no harm in applying.

Agree, nothing illegal with your employer reducing your hours unless you have a binding employment contract to the contrary.