Not an expert on this by any means, but you know those color blindness tests where there’s a bunch of red and green dots, the red dots form a number, and you ca

Not an expert on this by any means, but you know those color blindness tests where there’s a bunch of red and green dots, the red dots form a number, and you can only see the red number if you aren’t (that kind of) colorblind? It seems to be like that. From an article [1] summarizing work that claimed to identify one such woman: > Proving that these people actually see the world differently has involved a two-decade journey, however. Although the relevant combination of genes does not seem to be especially rare – perhaps 12% of women might have four distinct cones – many of the people that Jordan tested just didn’t seem to show any differences in their perception. But by 2010, she had found a subject who perfectly acted the part of a tetrachromat. Jordan’s “acid test” involved coloured discs showing different mixtures of pigment, such as a green made of yellow and blue. The mixtures were too subtle for most people to notice: almost all people would see the same shade of olive green, but each combination should give out a subtly different spectrum of light that would be perceptible to someone with a fourth cone. Sure enough, Jordan’s subject was able to differentiate between the different mixtures each time. “When you ask them to discriminate between the two mixtures, a tetrachromat can do it very quickly. They don’t hesitate,” says Jordan. [1] https://www.bbc.com/future/article/20140905-the-women-with-super-human-vision https://www.bbc.com/future/article/20140905-the-women-with-s...