theories of color vision

• trichromatic theory


  color vision is made possible by three types of cones, some of which respond to red light, some to green and others to blue

  -          based on an experiment made by Thomas Young

  -          could create any color from visible spectrum by simply varying the interactions of the light

  - Hermann Von Helmholtz, saw in Young’s discovery an explanation of color vision
• opponent-process theory


  also holds that there are three types of color receptors:

  -          hering suggested afterimages are made possible by three receptors: red-green, blue-yellow and a type that perceives difference in brightness from light to dark

  -          or Ewald Hering theory