Colored condoms would not work. You'd create a fuzzy dick hole which is just going to look weird and will never match up to the user's dick, which, btw, is either covered by a Handy or by the user's hand. Plus dick is usually in shadow so you can't even key it - green screen is lit. I keep seeing calls for keyed-out dicks but I don't think these guys have really thought it through, it would be a terrible idea. Really, really terrible. Maybe do it once, to prove how shit it is, but don't use a model the rest of us want to see filmed properly.