Color

Article By:

Weinacht, Thomas Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York.

Last reviewed:August 2020

DOI:https://doi.org/10.1036/1097-8542.149300

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• Color, published December 2018:Download PDF Get Adobe Acrobat Reader
• Color, published January 2014:Download PDF Get Adobe Acrobat Reader

The visual perception of different wavelengths of light. Light can be understood both as electromagnetic waves and as particles called photons. Photons can have different energies. The energy of a photon determines the frequency and wavelength of the wave. The full range of wavelengths is known as the electromagnetic spectrum, which spans from the longest wavelength (lowest frequency) radio waves to the shortest wavelength (highest frequency) gamma rays. In common usage, "light" refers to the small sliver of the spectrum that the human visual system is able to perceive—wavelengths between approximately 400 nanometers and 700 nanometers (1 nm = one-billionth of a meter). Each wavelength of visible light corresponds to a different color, which, in combination with other wavelengths, produces the rich palette of colors humans can distinguish (Fig. 1). See also: Color vision; Electromagnetic radiation; Electromagnetic wave; Light; Photon

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