Between the ages 11 and 13, I laboured under the delusion that cum was purple, and had the consistency of frogspawn. It was started by a child who claimed to have seen his brother’s spunk.
Being eager to impress, the next day I told my friends that I myself had come. Moreover, I claimed to have produced a pint of plum coloured spooge. I was hailed as a hero, until puberty let everyone know that I was either a liar or a freak...
It was at this point that I should have pointed out that the lie came originally from a boy who watched his brother wank.

A guy I was at school with called Mike, bumped into another old schoolmate in a pub in town. Mike's parents are Egyptian, so he had quite dark skin, hair etc. Anyway during a discussion on race relations in our rather provincial small town, he managed to convince this guy that because his skin was brown, his cum was brown too.