This is what everyone wants if he has got space and a ton of polystyrene. Well, it is too much white, maybe you can prefer a more masonry touch like actual Colosseum, but in the ancient times it was all covered by coloured marbles. So its aspect was almost white, after all. But not so white.

You can know more on this Colosseum in white here. A bit rough but great. And it is 20 years old!