I'd be interested in the best day time as well, but asked about night first as that might fit my schedule better.
I've looked up several online, but wd like to hear some recs from someone "live" and current.
Thanks so much!
https://search.ricksteves.com/?utf8=%E2%9C%93&query=Colosseum+changing&button=
A lot is currently changing. Good luck!
We took the Colosseum by Moonlight tour back in November and thought it was excellent. It may be more atmospheric than a daytime tour, with the darkness contrasting with the illuminated areas. However, note that the tour is limited, visiting only the underground and then some time up on the arena floor. So you may not find that it's enough to fully satisfy your curiosity - we had also scheduled a traditional entrance with audio guide the following day. But if you have limited time, it's a way to extend your touring day - we did the Borghese Gallery in the afternoon, stopped at Mercato Centrale in Termini for an early dinner, then went on to the Colosseum.
We had an excellent docent, who was quite knowledgeable.
Do you recall if you booked through Get Your Guide? Thanks.
We booked all of our Colosseum tickets directly from the official site, which was Coop Culture at the time. I was surprised at how available tickets for the moonlight tour were.
I don't know what the current situation is or which tours are available.