color palette
Also called a "color lookup table," "lookup table," "index map," "color table" or "color map," it is a commonly used method for saving file space when creating 8-bit color images. Instead of each pixel containing its own red, green and blue values, which would require 24 bits, each pixel holds an 8-bit value, which is an index number into the color palette. The color palette contains 256 predefined RGB values from 0 to 255.
Two or more 256-color (8 bit) images generally cannot display correctly side by side on a 256-color display, because there are too many colors for the system to handle. If the images have very similar colors, there may be little discrepancy, but if they are different, one or more images will suffer. The remedy is to average the palettes in an image editor or to reduce the number of colors to 128 for each (7 bit) image. See bit depth.
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| Color Palette Index |
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| The pixels in the image contain an index number, which points to the RGB value in the color palette. The RGB values are the ones used by the display system. |