Just a head's up that the Parco Colosseo site appears to be up and running for ticketing, and coopculture appears to be history for ticketing beyond this month. This is a VERY new development so apologies in advance but I just don't have answers to a lot of questions people may have. If you plan to visit beyond April 30th, you'll click the appropriate red box on the right side of the page. Hopefully,, as more of our helpful community has firsthand experience with it those questions can be answered! :O)
You are likely to experience a wait time - as it's showing currently- during periods of high volume traffic. It'll tell you how many minutes you'll be waiting in the queue. This website has also only been active in the past during hours the attractions are open; that may or may not change but for right now, I'd assume that's still the case.
This is the official website:
https://colosseo.it/en/