Traditional Culture Encyclopedia - Photography and portraiture - Three colors

Three colors

Red, yellow and blue are the three primary colors.

1, tricolor (tricolor)

Three primary colors refer to the three basic colors that cannot be decomposed. What we usually call the three primary colors, namely magenta, yellow and cyan. The three primary colors can be mixed into all colors and add up to black at the same time. Black, white and gray belong to colorless system.

In terms of color, the mixed color of the three primary colors is black, while the mixed color of the three primary colors as light-based materials is white due to the special properties of light.

Step 2 explain in detail

Three-color light model (English: RGB color model), also known as RGB color model or red, green and blue color model, is an additive color model, which adds red, green and blue colors in different proportions to produce various colors of light.

The main purpose of RGB color model is to detect, represent and display images in electronic systems (such as televisions and computers), but it is also used in traditional photography. Before the electronic age, based on human perception of color, RGB color model has a solid theoretical support.

RGB is a device-dependent color space: different devices detect and reproduce specific RGB values differently, because color substances (fluorescent agents or dyes) and their individual response levels to red, green and blue vary from manufacturer to manufacturer, and even the time of the same device is different.

Due to gamma correction, the color output intensity on computer display devices is usually not proportional to the R, G and B values in image files. That is to say, even if the value of 0.5 is very close to half of 0 to 1.0 (full intensity), the light intensity (0.5, 0.5, 0.5) displayed on the computer monitor is usually displayed (1.0, 1.0).

In the schematic diagram of color light additive method and pigment subtractive method, the left picture shows the three primary colors of color light: red, green and blue; The picture on the right shows the three primary colors of pigment: yellow, magenta and cyan.

The three primary colors of color light refer to red, green and blue, and their corresponding wavelengths are 700 nm, 546. 1 nm and 435.8 nm respectively. The three primary colors of light and objects are different. The three primary colors of light can be mixed in a certain proportion to present various light colors. According to the research results of Thomas Young and Helmholtz, these three primary colors are defined as red, green and blue (equivalent to the color feeling of red, medium green and ultramarine in pigments). The color TV screen is made up of these red, green and blue dots. Mixing these three primary colors in different proportions and intensities can produce various color changes in nature. The three primary colors of pigments and other non-luminous objects are magenta (equivalent to rose and pink), magenta (equivalent to deep sky blue and lake blue) and light yellow (equivalent to lemon yellow). The three primary colors (1781-1868) selected by the British chemist Faust can be mixed into various colors, but they cannot be mixed with black, and can only be mixed with dark gray. Therefore, in color printing, in addition to the three primary colors, a black version should be added to obtain deeper colors.

In fine arts, red, yellow and blue are defined as three primary colors, but magenta with a proper amount of yellow can set off scarlet (red =M 100+Y 100), but scarlet cannot set off magenta; Blue (blue =C 100+M 100) can be obtained by adding a proper amount of magenta to blue, but dark blue can be obtained by adding green to blue; More colors can be mixed with yellow, magenta and cyan, which are pure and bright. Green mixed with green and yellow (green =Y 100+C 100) is purer and brighter than green mixed with blue and yellow, while the latter is darker. Magenta and blue are pure purple (purple =C20+M80), red and blue can only get gray purple and so on. In addition, from the perspective of integrating other colors, yellow, magenta and cyan are all their primary colors, with richer colors and purer and brighter colors. (In 3D MAX, the three primary colors are red, yellow and blue)

reference data

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