Tetrachromats

Ooh, so cool! They have found a real tetrachromat!! Yes, two exclamation points, I know, but I'm excited. Tetrachromats are -- for those who haven't memorized Akira's speech about quirks and super-tasters -- people with four types of cone cells in their eyes. Theoretically, they would be able to see a range of colors enormously far beyond what ordinary people can see, but they would probably never know they were different, because how would they find out? Apparently, though, they are no longer theoretical: Humans-with-super-human-vision

To a tetrachromat, the rest of us are color-blind. But there's no way for them to explain the colors that they can see, because we have no shared language to use. It's a completely useless super-power. But very, very cool.