Up to 12% of Women Carry a Gene for 4-Dimensional Color Vision, Scientists Say. Most Never Develop It.

3 min readHere’s what you’ll learn when you read this story:Up to 12 percent of women carry gene variants for tetrachromacy, an enhanced form of color vision.While most people have three types of specialized cone cells to pick up on red, green, and blue light, tetrachromats have a fourth type of cone that is sensitive to the yellow-green portion of the visible spectrum.Simply having the hardware for tetrachromacy does not necessarily mean you will experience supercharged color vision.Concetta Antico calls herself “The Color Queen,” and for good reason: If you believe the San Diego, California–based painter, she can see up to 100 million distinct colors, or about 100 times as many as the rest of our plebeian eyes can discern. As an artist, you couldn’t ask for a better ticket in the genetic lottery; but Antico is not alone.About 12 percent of all women carry gene variants on their X chromosomes that may produce an extra photopigment, scientists say. So while most of us have three types of specialized cone cells in our retinas that pick up on wavelengths of red, green, and blue light, tetrachromats have a fourth type of cone.Perhaps the closest the majority of us will get to experiencing this feat of perception is through Antico’s body of work, which examines the interplay of color and light in the natural world. In one of her oil paintings, titled “Between the Devil & The Deep Blue Sea,” the moon peeks out from behind a thick curtain of clouds in a hazy sky, casting light on the ocean and a rocky cliff in the foreground. But she depicts the soft halo of light around the moon with more than the expected yellows and whites; there is a soft circle of green and even flecks of purple and pink.This isn’t creative license, Antico says. “I’m actually painting exactly what I see. If it’s a pink flower and then all of a sudden you see a bit of lilac or blue, I actually saw that,” Antico told The Guardian in 2022.Still, possessing an extra color receptor doesn’t automatically translate to supercharged color vision, scientists say. Even the scientists who have been studying Antico’s self-proclaimed superpower for over a decade can’t say for certain that she sees millions of different colors that the rest of us cannot. After all, we don’t just see with our eyes; we see with our brain. When you look at an object, light reflects from its surface and into your retina, where the cones live. Then, the retina converts that light into electrical signals your brain can process.So on its own, a fourth cone type is not enough to guarantee supercharged color vision; your brain needs to develop the neural pathways required to process that extra data as an independent source of color information. As a 2019 review of tetrachromacy research puts it: “Even with four types of cones, vision might remain trichromatic in the sense that only three variables are needed in a color-matching experiment. We have called this ‘weak tetrachromacy.’ The more interesting case is ‘strong tetrachromacy,’ where a woman requires four independent stimuli in matching colors.”Researchers who have worked with Antico believe she is one of these functional tetrachromats—likely because she’s been continuously painting since she was 7 years old, according to Kimberly A. Jameson, PhD, one of the scientists who has studied Antico. Still, that’s just a hypothesis. “This is how genetics works: it gives you the potential to do things and if the environment demands that you do that thing, then the genes kick in,” she told The Guardian. For most, this never happens.A genetic test can determine your potential for tetrachromacy, but it won’t tell you if you’re a functional tetrachromat like Antico. If you come across online tests that promise they can evaluate tetrachromacy, you should be dubious. According to Newcastle University, which runs the Tetrachromacy Project, computer screens are built on the red-green-blue color standard, so do not provide enough color information to tap into the extra dimension a tetrachromat may possess. “It is therefore impossible for an online test to investigate tetrachromacy,” the researchers note on the project website.Before joining Pop Mech, Courtney was the technology reporter at her hometown newspaper, the Pittsburgh Post-Gazette. She is a graduate of the University of Pittsburgh, where she studied English and economics. Her favorite topics include, but are not limited to: the giant squid, punk rock, and robotics. She lives in Philadelphia with her husband, her black cat, and towers upon towers of books.