Tetrachromats can see up to 100 million colors, which is 100 times more than the average person.

Human color vision typically relies on three types of cone cells in the retina, sensitive to short, medium, and long wavelengths of light. This standard vision is called trichromacy and allows for the perception of roughly one million distinct colors. Tetrachromacy occurs when a person possesses a fourth cone cell, expanding their color palette to an estimated 100 million variations.This condition is linked to the X chromosome. The genes for red and green pigments are located on this chromosome, and because women have two X chromosomes, they can carry two different versions of these genes. If these versions are distinct enough, it results in a fourth functional cone type. This is why the condition is found almost exclusively in biological women.In 2010, Dr. Gabriele Jordan from Newcastle University identified the first 'functional' tetrachromat, a doctor from northern England. While many women may carry the genetic potential for four cones, not all of them use the fourth cone to perceive a wider range of colors. The brain must be able to process the additional signals to truly experience this enhanced spectrum.Researchers believe that roughly 12% of women may have the genetic makeup for tetrachromacy, though true functional tetrachromats are much rarer. This discovery highlights the incredible diversity of human sensory perception. It suggests that the world looks fundamentally different to a small segment of the population based entirely on their genetic code.