Opposite color theory

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Color wheel according to Ewald Hering. The values ​​in percent reflect the proportions of the primary colors red, yellow, green and blue perceived simultaneously in a color field. According to this model, yellow and blue, for example, cannot be perceived in one color at the same time.
An afterimage is created when you stare at a bright square and then at a light surface.
Opposite colors

The opposite color theory (or opposite color theory ), also opponent theory , is a theory of human color perception . It was published in 1874 and 1878 by Ewald Hering (1834-1918) as an alternative to the three-color theory of Thomas Young and Hermann von Helmholtz .

Hering started from the observation that one cannot imagine color impressions such as “yellowish blue” or “reddish green” (mutual exclusion of yellow and blue or green and red). That is why he suspected three separate chemical processes in the retina, each with two opposing colors , with an inhibiting and an exciting component, which strive for equilibrium. The opposing color pairs are blue-yellow, red-green and black-white.

For the current state of knowledge, see color perception .

Origin of the pairs of opposites

The knowledge about the pairs of opposites mentioned above is based on the following observations:

  • When considering all color tones, the four colors red, green, yellow and blue appear to be particularly pure for most people. Hering called these colors the primordial colors. Other tones are always felt to be a mixture.
  • When looking at a colored area for a long time and then looking at a neutral, light area, afterimages are created in the respective opposite color. Nowadays this process is called successive contrast. The successive contrast ( successively = "successive") explains Hering follows: In the black and white process a perceived as a white stimulus have an inhibitory effect. However, since a balance is sought, after the stimulus (white) has been switched off, a black afterimage remains, which is caused by the dominance of the now predominant stimulating part of the process.

Look carefully at the center of the four-colored square for about 30 seconds. Then look at the field with the little dot in the middle. What did you notice?

Afterimages in opposite color

You will see an afterimage of the object in complementary colors . This phenomenon could not be explained with the three-color theory.

  • Colored surfaces influence the appearance of adjacent surfaces in the direction of their own opposite color (simultaneous contrast). The simultaneous contrast ( simultaneously = at the same time) arises after Hering follows: A stimulus stimulates not only the area he is concerned, but also the neighboring regions, but in the opposite direction. So z. B. a very bright or white environment can make an object appear black in the middle.
  • One cannot imagine mixed colors “yellowish blue” or “reddish green”.
  • Disturbances in color vision often manifest themselves in a loss of the ability to differentiate between blue-yellow and red-green.

Confirmation of the opposite color theory

Although Hering's ideas were simplistic, these three processes could actually be demonstrated. Since 1966, neurophysiological research has confirmed that there are four basic color sensations.

Three different types of cones in the eye, each of which is most sensitive to short (blue), medium (green) and long-wave (red) light, deliver signals to the downstream color-opposed ganglion cells of the retina (neural color channels). At the neural level, the spigot signals are "interconnected": "Red" and "Green" are subtracted, the difference is passed on in the red-green channel; the addition of “red” and “green”, on the other hand, produces a signal that corresponds to the perception of yellow; these signals are subtracted from the "blue" signal and passed on in the yellow-blue channel. All colors are also weighed against each other and combined in a signal in the black and white channel (see interconnection model ). As Hering postulated, three dimensions of perception arise: 1. Brightness, 2. Yellow-blue component, 3. Red-green component, from which several thousand types of color can then be distinguished.

Color space according to the opposite color theory

Color systems based on opposing color theory

Hering's opposite color theory forms the basis for the " Natural Color System " (NCS) used recently . The model of the Lab color space is also based, among other things, on Hering's counter-color theory.

literature

  • Johannes Webers: Handbook of film and video technology 8th edition, Franzis Verlag, 2007
  • Manfred von Ardenne: Effects of Physics and their Applications , Deutscher Verlag der Wissenschaften, 1988
  • Klaus Simon: Color in digital publishing. Digital color rendering concepts for office, design and software . Springer, Berlin 2008, ISBN 978-3-540-37327-8 (X.media.press).

Web links