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A CDE Definition

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red green blue

See RGB.


(1) (Red Green Blue) A designation for motherboards and peripherals that display colors for a visual effect. For example, an RGB keyboard has backlit keys that can alternate through a rainbow of colors. See RGB keyboard, RGB motherboard and RGB RAM.

(2) (Red Green Blue) The computer's native color space and the system for capturing and displaying color images electronically. All TV, computer and electronic display screens create color by generating red, green and blue (RGB) lights. This is because our eyes are sensitive to red, green and blue, and our brain mixes the colors together (see trichromaticity). See RGBW and RGBY.

Cameras and scanners capture color with sensors that record the varying intensities of red, green and blue at each pixel location in the frame. See 24-bit color, CCD sensor, CMOS sensor, scanner and digital camera.

Display and Printing (RGB and CMYK)
For screen display, red, green and blue subpixels (dots) are energized to the appropriate intensity. When all three subpixels are turned on high, white is produced. As intensities are equally lowered, shades of gray are derived. The base color of the screen appears when all subpixels are turned off.

For printing on paper, the CMYK color space is used, not RGB. Combinations of cyan, magenta, yellow and black ink make up the colors. White is typically derived by using white paper and no ink for those areas; however, if white is of critical importance, a white spot color can be added to the CMYK process. See CMYK and spot color.

Video Processing (RGB or YUV)
TV/video signals are mostly in the YUV color space. They are converted to RGB in the computer for editing when RGB is the desired output. If YUV is the desired output, and the video editing program supports YUV, there is no need to convert to RGB for internal processing. However, no matter which color space is used for editing, all data must be converted to RGB for screen display. See YUV, Adobe RGB, sRGB, color space and anaglyph 3D.

RGB Display and CMYK Printing
Display screens are RGB devices and have red, green and blue pixels. Printers are CMYK devices and use cyan, magenta, yellow and black inks. In theory, equal parts of cyan, magenta and yellow ink make black, but they tend to be muddy. Thus, black ink is used, making it a four color CMYK process (K for blacK). See CMYK.

RGB Color Conversions
Printing requires conversion from RGB to CMYK, and video editing requires conversion to and from RGB and YUV.

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