Standard Article

Color Vision

  1. Michael A. Webster

Published Online: 15 OCT 2004

DOI: 10.1002/3527600434.eap623

Encyclopedia of Applied Physics

Encyclopedia of Applied Physics

How to Cite

Webster, M. A. 2004. Color Vision. Encyclopedia of Applied Physics. .

Author Information

  1. University of Nevada, Department of Psychology, Reno, USA

Publication History

  1. Published Online: 15 OCT 2004


Color provides important cues to both the nature and location of objects in our environment. Normal human color vision is trichromatic because it depends on sampling the light spectrum with three classes of cone photoreceptor maximally sensitive to short, medium, or long wavelengths. Most forms of color-blindness are genetic and result from losses or alterations of the cone photopigments. Postreceptoral neurons sum the cone signals to form luminance-sensitive channels and contrast them to form color-opponent channels. Color opponency is suggested by both physiology and color appearance, though higher stages of color coding in the visual system remain unclear. Perceived color is strongly affected by adaptation to colors viewed previously and by induction from surrounding colors. These processes help normalize the response to color and contribute to color constancy for objects viewed in different lighting.


  • color;
  • vision;
  • trichromacy;
  • photopigments;
  • color opponency;
  • color-blindness;
  • adaptation;
  • color constancy