Color

Color is the perceptual experience derived from the interaction of light with the human visual system. It describes attributes such as hue, saturation, and brightness that arise from the spectral composition of light and the way surfaces reflect or emit it. Different wavelengths and combinations of wavelengths are interpreted as different colors, and context can affect perception.

Visible light spans 380 to 740 nanometers. Objects appear colored because they absorb some wavelengths and reflect others. The perceived color depends not only on the light source but also on adaptation and surrounding colors. Color temperature and metamerism (two light sources producing the same color on a surface) are notable phenomena; color perception involves constancy under varying illumination.

Color spaces and models formalize color for computation. Hue, saturation, and brightness (or value) describe perceptual properties, while numerical spaces such as RGB, HSV, and HSL map colors to coordinates. In printing and pigment work, subtractive color mixing uses cyan, magenta, and yellow (often with black), whereas additive mixing of lights uses red, green, and blue.

Standards of color measurement include colorimetry and spectrophotometry, which yield tristimulus values and facilitate device-independent representations such as the CIE XYZ and CIELAB spaces. Digital displays typically reproduce color via RGB, with sRGB as a common standard; printers use CMYK and printer profiles to manage color.

Color has cultural and artistic significance and is central to design, branding, photography, and art. Variations in color perception exist among individuals, notably color vision deficiencies, and color naming and symbolism vary across languages and cultures.

Historically, color theory evolved from Newton's prism experiments to gestalt concepts and the development of standardized color spaces by artists and scientists, including the Munsell system in the early 20th century. Today, color science integrates physics, physiology, and computation to describe and reproduce color consistently.