In a revelation that has stunned color theorists and casual rainbow lovers alike, scientists have uncovered that purple isn’t a “real” color at all, at least not in the way we understand light and wavelengths.
Unlike red, green, or blue, purple doesn’t correspond to any single wavelength of light. Instead, it’s a brilliant illusion crafted by the human brain, a kind of mental shortcut to bridge the gap between colors on opposite ends of the spectrum.
Truth Behind Color Illusion
While every color in the rainbow has a specific place on the visible spectrum, purple is mysteriously absent. That’s because it doesn’t exist as a standalone wavelength.

It doesn’t appear in ROYGBIV- Red, Orange, Yellow, Green, Blue, Indigo, Violet because there’s no “P” in the rainbow. Violet, the final color on the spectrum, does have a wavelength, but purple is a neurological invention.
“Purple, then, is not the product of a direct stimulus but a neural illusion,” scientists explained.
The science behind this illusion lies in how the human eye perceives light. We see color through three types of cone cells in the retina, each sensitive to short (blue), medium (green), and long (red) wavelengths.
When red and blue light hit the eye simultaneously, the brain imaginatively ‘fills in’ a new color to make sense of it all and that imagined color is purple.

Purple in Nature’s Spectrum
“When you look at a rainbow, you’ll never find purple. It’s not because it’s missing, it was never there, to begin with,” researchers emphasized.
This is because red and blue sit at opposite ends of the color spectrum, and there’s no physical wavelength that naturally blends the two.
Unlike orange, which sits between red and yellow, or cyan, which lies between green and blue, purple is a mental workaround- a color born not from light, but from perception.

Color Born in the Brain
Despite being a figment of our visual processing system, purple has carried immense weight throughout history. Often associated with royalty, mystery, luxury, and spirituality, purple’s cultural and symbolic significance far exceeds its non-existent spectral presence.
This discovery is more than a fun fact- it’s a remarkable example of how the brain interprets reality. It shows that what we see isn’t always what’s actually there, and how perception can shape what we consider truth.
Scientists say that humans perceive only about 0.0035 percent of the electromagnetic spectrum, and purple’s very existence highlights just how much of the world is filtered and translated by the brain.
So next time you see a field of lavender or admire a royal robe, remember: purple is proof that your brain is a master illusionist.