Here’s what you’ll learn when you read this story:The human eye does not actually see purple, as purple is not a color on the visual spectrum. The visible light spectrum detectable by human eyes makes up only a small fraction of wavelengths (0.0035%, to be exact). Cone cells come in : short wavelength cones (S), medium wavelength cones (M), and long wavelength cones (L). The shortest wavelength detection made by your S cones (violet light) has no overlap with the longest wavelength detection made by your L cones (red light). To compensate, the brain bends the spectrum into a circle, making the two extremes meet at purple.