I took a few pictures of dt Denver, Before I came down to Colorado Springs.
There are no restrooms in the big ass transit building and the cops love to harass the homeless, as usual. Colorado loves to shit on people that have already been shit on. They tried to ban feeding people in parks and shit.
There are bathrooms at Union station. They're at both ends. The one set is down in the bus round, just past the security kiosk, behind the escalators. Those ones are usually out of service.
If you go to the other end and up the escalators and outside. The Amtrack station has some bathrooms that are usually functional.