This is an article about colors, written by a person who is colorblind. Impossible, you say? So did this writer. In the course of protesting this assignment, however, it was pointed out that this writer frequently writes about topics that are utterly beyond his comprehension such as quantum physics, sports, and friendship. That being the case, why not add colors to the list?
And as long as we’re talking about a seemingly impossible task, why not sweeten the deal and make the article about impossible colors? What are impossible colors? They are colors that are not possible.
OK… Am I done? No? Alright…. Roll up your sleeves and join me in figuring out why you can see colors that cannot possibly exist.
How We Perceive Colors
One way of describing colors is to say that they are the manner by which our eyes interpret different wavelengths of light. The visible spectrum ranges from 380 nanometers to 700 nanometers. Our eyes see light at 580 nanometers as yellow, for example. Blue is what we see when light is at 450 nanometers.
We say “our eyes” see color in this way only in general terms. As has already been pointed out, some of us are colorblind. This is not as small of a subsection of the population as you might imagine. One out of every 12 (8%) men and one out of every 200 (0.5%) of women experience some form of colorblindness. This is because of a defect in the eyes.
The retina covers the back of the eyeball. It consists of rods and cones. Rods are valuable in allowing us to see in low light and to give us peripheral vision. Cones are what allow us to see colors.
In the normal human eye, there are three types of cones, each attuned to different wavelengths of light. They are unimaginably called short-wavelength sensitive cones (S-cones), middle-wavelength sensitive cones (M-cones), and long-wavelength sensitive cones (L-cones). L-cones are stimulated by red light. M-cones are triggered by green light. S-cones are reserved for blue light.
In case you haven’t noticed, the last time you picked up a box of crayons, there were a lot more than three colors in the box. Red, green, and blue are just fine if all you are going to do is color a picture of Donald Duck’s nephews, Huey, Dewey, and Louie. There are plenty of other things to color, however, so our cones helpfully pick up more than their one pure color. When you see yellow, for example, it is a result of both the red and green cones being stimulated. Your brain interprets these signals as yellow, the color that appears between red and green in the color spectrum.
The Color Spectrum
The main colors of the color spectrum and the order in which they appear can be shown through the helpful mnemonic ROY G. BIV:
All of the colors possible in the visible light spectrum are found in the range of the ROY G. BIV color spectrum.
So What About Magenta?
This brings us to the first color that you shouldn’t be able to see. Behold the color magenta, or as it is affectionately referred to by this writer, Hex FF00FF, since that is the only way for a colorblind person to look up the right color. Magenta is sort of a reddish-purple that is almost-but-not-quite the color of royalty, singing dinosaurs, and ruptured blood vessels.
What’s wrong with magenta? Take another look at the ROY G. BIV spectrum. You won’t find magenta anywhere on it. It does not exist within the range of visible light. How is it, then, that we see this unnatural color? (Again, we use “we” loosely.)
Magenta is what we see when light stimulates the retina’s red and blue cones at the same time. Ordinarily, the brain takes multiple cone signals and averages them. The mid-point between red and blue on the spectrum is green. One would think that this is the color we would see in this situation. The problem is that the brain knows you are really seeing green when the green cones are being stimulated. Since nothing is tickling your green cones, your brain knows it is supposed to be seeing something, but it can’t be green. Left with no other option, your brain basically freaks out and invents something imaginary. It’s not unlike a mild form of PTSD, where your brain invents memories to compensate for an experience that is just too horrible to relive, such as the movie version of Cats.
Magenta may be called an impossible color, but you obviously see it all over the place. There are other impossible colors that can be “seen,” despite the fact that they don’t exist anywhere in the world. These are called “Chimeral Colors.” They can be seen temporarily through some optical sleight-of-handedness. Chimeral colors come in four types.
The first chimeral color is called hyperbolic. This sounds like a trendy new dance or a nausea-inducing roller coaster. It actually refers to colors that theoretically exist but cannot be seen under ordinary circumstances.
The cones overlap each other in terms of the wavelengths that trigger them. The green cones, for example, will never be exposed to light to which they are exclusively stimulated. There will always be some triggering of either the red or blue cones. When Kermit the Frog sings, “It’s Not Easy Being Green,” perhaps this is what he was referring to.
But what if you wanted to see a green that is greener than any green you have ever seen? First of all, that sounds like the perfect opening line to a Dr. Seuss book. Secondly, seeing that color might be a possibility if there was some way in which you could trigger solely your green cones without interference from the others. If you could do that, you would be able to see the impossibly-vibrant color hyperbolic green.
Hyperbolic green may be theoretical, but there is a way you can experience it — assuming, that is, that you have properly-functioning cones and are able to follow directions. You can trick your eyes into thinking that they are seeing this impossible color. To do this, stare at magenta for about 20 seconds. When you do this, you send your red and blue cones into hyperdrive. They quickly become fatigued. As a result, when you look away, you will see an after-image of green, since your green cones are the only ones that are not gasping for breath. If you then immediately look at green, the green after-image will combine with the green you are looking at, giving you a brief glimpse of hyperbolic green.
A similar phenomenon occurs when you stare at cyan and then look at orange. The result allows you to see hyperbolic orange.
A video demonstration of this phenomenon follows later in this article.
Stygian colors are another type of chimeral color. These colors are seen as both black and an impossibly-saturated version of its true pigment. Stygian blue, for example, is seen as both black and blue — much like this writer appeared shortly after trying to stand up to the school bully in the fifth grade.
To see stygian blue, stare at yellow for about 25 seconds. This will fatigue your red and green cones. Then stare at black. The after-image of blue will appear. Only your blue cones are unfatigued at this point, so they also light up, giving you a full-blue experience while simultaneously allowing you to see black. In other words, you see black against blue at the same time that you see blue against black.
Again, stick around for the video demonstration later on.
Self-luminous colors appear much brighter than they should be. It’s sort of like Britney Spears winning an episode of Jeopardy! Sure, it might be fascinating to watch, but deep down, you know that sort of thing isn’t going to happen naturally.
To experience the phenomenon of self-luminous colors, just stare at a color for about 25 seconds and then look at white. The after-image will be the self-luminous version of its opposite. If you stare at green and then look at white you will see self-luminous red, because red is the opposite of green. Look at yellow, then white, and you see self-luminous blue because blue is the opposite of yellow. Presumably, if you stare at Albert Einstein before looking at white, you’ll see self-luminous Britney Spears. Again, this writer is colorblind, so it couldn’t be put to test before publication.
A demonstration of how to see hyperbolic, stygian, and self-luminous colors can be seen in the following video:
Impossible Combination Colors
Are you familiar with those optical illusions where an image can appear to be more than one thing? Consider this famous example:
It could be a duck. It could also be a rabbit. You can see it either way. Now try seeing both a duck and rabbit at the same time. You can’t do it, can you? Your brain tells you that it has to be one or the other.
In a way, this explains the final chimeral color type, “Impossible Combination Colors.” In the theory of Opponent Process, you cannot see any colors that would be described as a combination of two opposites. You can see red or green, but there is no such thing as a “reddish green.” You can combine red and green light, but that gets you yellow. If you mix red and green paint, you get brown. There’s no way of coming up with a “reddish green.” Similarly, you can see blue or yellow, but not “bluish-yellow.” You can see pizza, and you can see pineapple, but not even in the Infinite Universe theory is there a world where the two can be combined without offending all of the laws of nature.
You might, however, be able to achieve the impossible — assuming you have two working eyes, that is. If you stare at each of the following groups of two opposite colors and allow your eyes to cross, the resulting image should give you the color combination that could not otherwise be produced.
If, however, you look at pizza and pineapple and get this:
Well…. there’s just something wrong with you.