We got a much earlier start the next morning - no more sleeping until 10:30 again on this trip!
I had read online that the best time to visit was early in the day, before the crowds really picked up and the tickets lines got backed up. Our tickets from the Roman Forum and Palatine Hill the day before were also good for the Colosseum the next day, so we were able to skip that line and get in with only a little bit of a wait.
...but you could still find quiet spots here and there.
...that was full of stalls selling all sorts of delicious food. Fruits and veggies and flowers and juices and tables heaped with pastas...it was really cool. We spent a while wandering around before eventually making our way back to the hotel via a tram and the Metro.