The Color Purple is not Real

The scientific idea that the color purple does not physically exist, and that what we perceive as purple is actually the brain’s interpretation of something between red and blue, is rooted in the principles of color perception and the physiology of human vision.

The Concept of Color

Color, as perceived by humans, is not a physical attribute of objects but a result of how our eyes and brains interpret different wavelengths of light. The visible light spectrum consists of electromagnetic waves with varying wavelengths, where different wavelengths correspond to different colors. For instance, shorter wavelengths appear as blue, medium wavelengths as green, and longer wavelengths as red (Palmer 47).

Purple as a Non-Spectral Color

Unlike spectral colors, which correspond to single wavelengths of light, purple is a non-spectral color. Spectral colors include those found in a rainbow, where each color is linked to a specific wavelength. Purple, however, does not have a corresponding wavelength. It is a color that our brain perceives when it receives a combination of red and blue light. This combination occurs because of the way our eyes process light through cone cells sensitive to different wavelength ranges (Zeki 55-57).

Color Perception and the Brain

Human eyes contain three types of cone cells, each responsive to different portions of the light spectrum: short-wavelength cones (sensitive to blue), medium-wavelength cones (sensitive to green), and long-wavelength cones (sensitive to red). When both red and blue wavelengths enter the eye simultaneously, they stimulate these cones in a particular way. The brain processes these signals and blends them to create the perception of purple. Thus, purple is not a "real" color in the physical sense but a construct of the mind that exists only in our perception as a mixture of red and blue wavelengths (Livingstone 84-86).

Metamerism and Subjective Color Experience

The concept of metamerism further explains how different combinations of wavelengths can produce the same perceived color. For example, while no single wavelength corresponds to purple, the brain perceives it when red and blue light are combined. This blending process reflects how the brain simplifies and interprets the complex spectrum of light into the colors we perceive. It highlights that color perception is subjective and influenced by both the physical properties of light and the brain's interpretative processes (Palmer 62; Zeki 59).

The Color Purple is not Real

Purple is an example of how the brain constructs color from the available sensory information. While it does not exist as a distinct wavelength of light, the color purple is created by the brain’s interpretation of overlapping red and blue wavelengths. This understanding underscores the idea that color is not an objective property of the world but rather a subjective experience shaped by our sensory and cognitive systems.

Works Cited

Livingstone, Margaret. Vision and Art: The Biology of Seeing. Abrams, 2008.

Palmer, Stephen E. Vision Science: Photons to Phenomenology. MIT Press, 1999.

Zeki, Semir. A Vision of the Brain. Blackwell Scientific Publications, 1993.