The search for new colors is an enduring quest in the world of art, science, and technology. While the visible color spectrum appears limited to the rainbow colors we can see with our eyes, the possibility remains that new colors could be created through ingenious methods. This article will explore the science behind color, examine attempts to create new colors, and consider whether undiscovered colors are still out there waiting to be found.
The Science of Color
To understand if new colors are possible, we must first comprehend how color works. Visible light is part of the electromagnetic spectrum. It comprises wavelengths ranging from about 400 to 700 nanometers. The wavelengths interact with the cone cells in our eyes, which allow us to see different colors. Red light has the longest wavelengths, while violet has the shortest. When all visible wavelengths of light are combined, they appear white to our eyes.
The range of colors we can experience depends on the number of unique cone cells in our retinas. Most people have three types of cones, which are sensitive to red, green, and blue wavelengths. The stimulation of these cones in different combinations allows us to see the entire rainbow of colors. So within the visible light spectrum, it appears unlikely that extra colors exist outside of red, orange, yellow, green, blue, indigo, and violet.
However, that has not deterred attempts to push the boundaries of human color perception.
Inventing Impossible Colors
Is it possible to trick the eye and brain into seeing a color not found in the rainbow? Some scientists and artists have tried to create optical illusions of “impossible colors” that cannot exist within the visible light spectrum. Given that color is a construction of our visual cortex, might we be able to hack it somehow?
One famous example is stygian blue. In 2018, ophthalmologist Claude Monet developed a shade of blue that appears to be brighter than the brightest blue wavelength of light. This is physically impossible under normal conditions. The stygian blue illusion works by fatiguing the eye’s blue receptors and then presenting yellow dots on a blue background. The yellow appears stygian blue, even though no light at that wavelength enters the eye.
Other engineered colors include hyperbolic orange and greenish purple. These colors appear unnaturally saturated and metallic. They represent what a color might look like if its wavelength were able to extend just a tiny bit beyond the visible spectrum’s limits.
So in a sense, scientists have created new colors not found in nature. But they only work as illusions seen under specific, controlled conditions. These colors do not represent an actual expansion of the visible color spectrum itself.
Color Spaces Beyond RGB
Another way people have searched for new colors is by exploring color systems beyond the traditional RGB (red, green, blue) color model. RGB works by creating different hues through combinations of red, green, and blue light. This mimics how our eyes’ cone cells operate.
But perhaps new colors could emerge with a fundamentally different color system. For example, the CMYK (cyan, magenta, yellow, black) color model used in printing combines these four inks to generate a range of colors through reflection and absorption. By modifying CMYK inks, some artists have created distinct colors not reproducible with RGB light. However, these remain constrained to existing color perception and are not true spectral colors.
There is also HSL (hue, saturation, lightness), which decouples hue from brightness. Twirling around the HSL color wheel produces intensely vivid hues. Software programs can display these hyper-saturated, non-spectral colors. But ultimately, they still trick the eye within the limits of our cone cells. The HSL color circle does not reveal previously unseen colors.
Varying Color Reception
Another consideration is that not all people see colors identically. Color perception can vary based on differences in eye biology. For example, some people have four cone cell types instead of three. This extra dimension in color vision is called tetrachromacy.
Tetrachromats may be able to perceive 100 million more colors than the rest of us. This includes reddish greens, yellowish blues, and other hues virtually unimaginable to someone with normal trichromatic vision. Estimates suggest tetrachromats make up between 1-2% of the female population, while truly tetrachromatic males are extremely rare.
So in a sense, a tetrachromat might answer “yes” to whether new colors exist—at least ones new to you or me. But scientifically speaking, tetrachromatic vision still operates within the usual visible spectrum. It simply allows more perceptible combinations and gradients within that gamut.
Color Constancy and Contrast Effects
Context also changes color appearance. The exact wavelengths entering your eye may stay constant, but surrounding colors influence how the brain interprets them. This effect, called color constancy, accounts for differences like an object appearing white under blue daylight but yellow under incandescent lights. The brain automatically color balances based on environmental cues.
Contrast effects also enable colors to transform one other. For example, staring at a bright green image for 30 seconds and then quickly switching to a gray background can make the gray seem tinted pink. This negative afterimage occurs because the eye overcompensates after adapting to the green. While interesting, afterimage colors do not truly reveal unseen hues either.
Expanding the Color Spectrum
Given the science behind human color vision, is it physically possible we could one day experience infrared or ultraviolet colors? These wavelengths of light exist beyond the visible spectrum. Infrared has longer wavelengths than red light, while ultraviolet has shorter wavelengths than violet.
We know insects, birds, reptiles, and other species can see these hidden colors. shrimp have 12-16 types of cone cells, so their world is incredibly rich with colors we cannot imagine. Evolution endowed these species with the biological capability to beneficially detect UV or infrared waves in their environments.
Hypothetically, if scientists could safely add a new type of cone cell to a human retina, maybe we too could see infrared’s redder reds or ultraviolet’s violeter violets. Perhaps even X-ray or gamma ray vision could be possible, with the right modifications. But this currently remains solidly in the realm of science fiction.
Realistically, the only way to visualize finer Spectral variations beyond our inborn limits may be through technology. Sensors could detect infrared or UV light and convert those wavelengths into visible colors tailored to human eyes. Augmented reality glasses could then overlay the new colors onto the world. Potentially we may all one day digitally expand our color perception.
Do Undiscovered Colors Exist?
So in summary, we have not yet reached the limits of color itself. Scientists continue using technology to uncover shades undetectable to our natural senses. New awe-inspiring colors may wait for us out there somewhere in the far reaches of space. But practically speaking, human color perception appears confined to the visible spectrum of wavelengths.
We cannot physically experience infrared or UV hues directly with our biological eyes. Clever optical illusions and hypersaturated effects only work within our existing trichromatic vision. Even the expanded perceptual palette of tetrachromats still operates within that 400 to 700 nanometer gamut.
In the end, the only way we know of to truly see new colors is through technological augmentation. But until science fiction becomes reality, no one has of yet invented an actual new color discernible by the unaided human eye. The rainbow we have seems likely complete, waiting to be fully explored and appreciated for the wonder it is.
While the search continues, humans have so far not created or discovered any verifiable new colors. Our eyes and brains evolved to convert wavelengths of visible light into the familiar rainbow spectrum. Scientists have explored optical tricks that appear to reveal impossible shades. Engineers have rendered hypersaturated digital colors. But no one has unlocked hidden hues outside the physical limits of our visual cortex. Augmented reality may one day reveal unseeable colors from infrared to X-rays. For now, the approximately 100 trillion shades perceivable to the human eye remain more than enough wonder for artists, designers, and vision researchers alike to explore.