Yes, here is the description from the Roman Guy
After the daytime crowds are gone, experience Ancient Rome and the Colosseum at night. This evening tour also gives you access to both the Underground and Arena Floor, when there's almost nobody else inside the Colosseum. Spaces on this tour sell out fast - book now to avoid disappointment. And when we say no crowds, we mean it! In fact, you might not see another tour group while you're inside the Colosseum. If you've seen how popular the amphitheater is during the day, then you understand what a rare opportunity this is.