[morb]

Years ago Radiolab did an episode on colors: http://www.radiolab.org/story/211119-colors/

In the second segment they introduce a potential tetrachromat, Susan Hogan (not the same person as this article). I don't remember if her tetrachromacy was confirmed a real science experiment, I don't think it was.

But I'd still recommend the whole episode. All three segments were pretty interesting.