Psychology Wiki

Additive colors

Redirected from Additive color

34,200pages on
this wiki





File:RGB illumination.jpg


Computer monitors and televisions are the most common form of additive light. The colored pixels do not overlap on the screen, but when viewed from a sufficient distance, the light from the pixels diffuses to overlap on the retina. Another common use of additive light is the projected light used in theatrical lighting, such as plays, concerts, circus shows, and night clubs.[1]


File:Tartan Ribbon.jpg
File:J C Maxwell with top.jpg

James Clerk Maxwell is credited as being the father of additive color.[2] He had the photographer Thomas Sutton photograph a tartan ribbon on black-and-white film three times, first with a red, then green, then blue color filter over the lens. The three black-and-white images were developed and then projected onto a screen with three different projectors, each equipped with the corresponding red, green, or blue color filter used to take its image. When brought into alignment, the three images (a black-and-red image, a black-and-green image and a black-and-blue image) formed a full color image, thus demonstrating the principles of additive color.[3]

The following flowchart demonstrates an example of the process, step by step.

Light source Medium wavelengths, or green, and long wavelengths, or red, radiate from two different projectors.
Projection screen Both the medium and long wavelengths reflect off of a spot on the screen.
Retina The medium and long wavelengths activate M and L cones on a spot on the retina.
Brain The brain interprets the equal amounts of medium and long signal as yellow.

To fully understand the process, it should be demonstrated how dull colors are obtained using cyan, magenta, and yellow instead of red, green, and blue.

Light source Cyan, or SM, and yellow, or ML, radiate from two different projectors.
Projection screen Both the SM and ML reflect off of a spot on the screen.
Retina Some short, lots of medium, and some long wavelengths activate cones on a spot on the retina.
Brain The brain receives signals from the cones about some short, lots of medium, and some long wavelengths. It interprets the signal as light green.
If the background is not black, it interprets the signal as dull green.

See alsoEdit


  1. David Briggs. The Dimensions of Color. URL accessed on 2011-11-23.

External linksEdit


Around Wikia's network

Random Wiki