Tetrachromats can see colors that most people cannot — up to 100 million, estimates suggest, which is 100 times that of the average human. Most people have three cells, or receptors, in their retinas, but tetrachomats have a fourth receptor, which may be what allows for their heightened color perception. They are usually female, and it’s estimated that about 12 percent of women carry the gene for this fourth receptor. Carrying the gene doesn’t guarantee that you’ll wind up with heightened color vision, but those who both have the gene and who are immersed in a wide range of colors from a very young age appear to be more likely to develop the ability. Researchers are still in the very early stages in their understanding of this condition, so there aren't any hard numbers on how often it manifests itself.

Concetta Antico, a tetrachromat artist and oil-painting teacher from San Diego, recently spoke with Science of Us about her hyper-charged color perception.

Can you describe how something very familiar to everyone with ordinary color perception looks to you?

Let’s take mowed grass. Someone who doesn’t have this genetic variation might see bright green, maybe lights or darks in it. I see pinks, reds, oranges, gold in the blades and the tips, and gray-blues and violets and dark greens, browns and emeralds and viridians, limes and many more colors — hundreds of other colors in grass. It’s fascinating and mesmerizing.  

What about rain and snow or rainbows?

Snow is very colorful. Just think of many pastel colors. That’s what I see in white snow, like a white opal. Rainbows are breathtaking — they contain hundreds of subtle colors. I can stare for ages and not see them all.  That’s also what it’s like when I look at water and rain and snow and fog.

So tetrachromats are to sight what supertasters are to taste?

Exactly!

Except that 25% of people are tetrachromats.

https://www.linkedin.com/pulse/25-people-have-4th-cone-see-colors-p-prof-diana-derval

Supertasters are a much smaller percentage. 

"You see between 33 and 39 colors: you are a tetrachromat, like bees, and have 4 types of cones (in the purple/blue, green, red plus yellow area). You are irritated by yellow, so this color will be nowhere to be found in your wardrobe. 25% of the population is tetrachromat."

That's amazing.  I read somewhere never to paint the master bedroom yellow or it would lead to frequent arguments with your spouse!