After several days of immersive art-nerding with the brilliant creatives at the ÀNI Art Academies Dominicana, I hopped online and—bam—there it was again: another video claiming that “purple doesn’t exist.” Ugh. This tired claim was, once again, “supported” by the observation that purple is a non-spectral color and that “your brain makes it up.” Double ugh.
Let’s clear this up once and for all.
The Origin of the Claim
The idea that purple is not a “real” color arises from a fundamental misunderstanding of how human color perception works. The argument often stems from the fact that purple is a non-spectral color, meaning it cannot be produced by any single wavelength of visible light. But this technical fact about stimulus origin does not equate to a difference in perceptual legitimacy or “realness.” The suggestion that purple is somehow less authentic than spectral hues is scientifically inaccurate, linguistically misleading, and philosophically confused.
So What Is a Non-Spectral Color?
A non-spectral color is a perceptual experience that cannot be triggered by any single wavelength of light. Instead, it results from the brain’s processing of combined stimulation of multiple photoreceptor types. These colors occupy meaningful positions in perceptual color spaces but lack a one-to-one match with a pure light source.
Examples include: Purple, Magenta, Pink, Brown, Grays, and Desaturated hues (e.g., low-chroma pastels).
In the case of purple, a standard human observer’s trichromatic vision produces the experience when short-wavelength (S-cone) and long-wavelength (L-cone) photoreceptors are stimulated simultaneously, with minimal activation of middle-wavelength (M-cone) receptors. There is no single “purple” wavelength—but the resulting neural signal is clear, consistent, and categorically recognized across observers.
Also, All Color Is Neural—Not Physical
Color is not a property of light. Light carries physical properties such as wavelength and intensity—but color itself is a perceptual event, constructed by the brain in response to incoming light stimuli.n
To claim that a color is “not real” because it lacks a unique wavelength is to misunderstand the very nature of perception. Vision is not a passive readout of external properties—it’s an active, constructive process shaped by evolution, experience, and neural architecture.
As vision science has shown repeatedly perception is not about replicating the physical world—it’s about generating adaptive, internally consistent interpretations of ambiguous stimuli.
Purple Exists in All Major Color Models
Purple isn’t excluded from scientific understanding—it’s baked into the very models used to define perceptual color. In the CIE chromaticity diagram, purple appears in the “line of purples,” connecting the short- and long-wavelength extremes (~400–700 nm). These hues do not exist in the spectrum, yet they are routinely and reliably perceived.
Such models don’t “make exceptions” for purple. They require it.
Can I be any More Clear when I Say that “Purple Doesn’t Exist” is Fallacious on Every Level
Let’s break it down:
Linguistically, the claim fails to distinguish between a physical stimulus (wavelength) and a perceptual experience (color). Purple is not found in the light—it is found in the mind. Just like red, green, or blue.
Scientifically, it ignores decades of evidence showing that color is an interpretive outcome of visual processing, not a property of objects or photons.
Logically, it implies that only spectral stimuli can produce “real” experiences, which would invalidate half the perceptual world—including shadows, highlights, and nearly every complex color we see.
Seriously: Purple Is Fully Real
Purple is a real color—just like any other—because it is consistently evoked by specific neural activity and is fully integrated into modern perceptual models. Its status as a non-spectral color does not diminish its authenticity; rather, it highlights the remarkable, constructive nature of human vision.
To say that purple “doesn’t exist” is to reject the foundations of perceptual neuroscience, and to mislead audiences about how vision actually works.
Purple exists—exactly where all colors do—within the dynamic and interpretable activity of the human visual system.