The Hidden World of Color … at Least to Humans

Ralph Bernhardt, Reporter

You’ve probably heard that dogs can’t see the same colors humans do. This is because their eyes pick up different wavelengths of light than us and allow them a narrower set of colors to identify. While some creatures are colorblind, many animals and insects see colors that we cannot even conceive. For example, spiders and bees can both detect ultraviolet light, which is invisible to humans. Fish can often only detect two colors, while many snakes can detect thermal light.

Humans can usually detect between 10 million and 16 million unique colors, which, compared to most species, is a lot. However, some species of birds and insects can detect more than 10 billion colors due to their unique eyes. While humans have three types of cone cells – for yellow, red and blue, some animals have as many as five, while others (such as seals) have just one. With fewer cones, some colors tend to blend together. For example, dogs, with just two unique cone cells, have trouble distinguishing colors such as red and green.

While you can’t expand your color vision, you can see seemingly unique “impossible colors” through optical fatigue. By glancing at a blue light before looking into an orange screen, you might see “hyperbolic orange,” which is more orange than the “orangest” orange – beyond 100 percent saturation. Alternatively, you might see the poetically named Stygian Blue by glancing at a yellow light before looking toward darkness. The effect will be both black and blue at the same time. Stygian is the adjectival form of Styx, which, according to Greek myth, flows through the Underworld. The River Styx is described as simultaneously blue as well as the blackest black.

“Impossible colors” may be the closest we can get to expanding our color vision, but that’s not necessarily something to weep about. While it’s true that humans certainly don’t have the best color perception of any animal, we are far from the worst. Some weak-visioned creatures, like dolphins and owl monkeys, perceive fewer than 100 unique colors, making 16 million sound pretty impressive. Such creatures are called monochromats, with just one unique cone recepter. So, whenever you feel bad about your poor vision, partial color-blindness or thick lensed glasses, just remember that at least you aren’t an Australian sea lion.