In theory, any color can be mixed with the three basic colors—red, green, and blue (RGB) in different proportions. The stronger the light intensity of the three colors, the more light reaches our eyes. If no light reaches our eyes, it is pitch black. The proportions of color and light mixing are different, and the colors we see are different. When the three primary colors are added at different intensities, the total light intensity is enhanced, and any color can be obtained.
The relationship between a certain color and the three primary colors can be described by the following formula:
Color = R (percent red) + G (percent green) + B (percent blue)
- Red (100%) + Green (100%) + Blue (100%) = White
- Red (100%) + Green (100%) + Blue (0%) = Yellow
- Red (100%) + Blue (100%) + Green (0%) = Magenta
- Green (100%) + Blue (100%) + Red (0%) = Cyan
As stated above, when the three primary colors are added in equal amounts, white is obtained; when equal amounts of red and green are added and blue is 0 value, yellow is obtained; when equal amounts of red and blue are added and green is 0, magenta is obtained; etc. A cyan color is obtained when the amount of green and blue is added and the red is 0. The color mixing effect of the three primary colors and the RGB color space are shown in the figure:
The cathode ray tube (CRT) used in televisions and computer monitors is an active device. The CRT uses 3 electron guns to generate light in three wavelengths of red (Red), green (Green) and blue (Blue). The different relative intensities combine to produce color. Combining these three light waves to produce a specific color is additive color mixing, called the RGB additive model. Additive color mixing is the basic method for defining colors in computer applications.