indexed colour

Definition: Method of creating colour files or defining a colour space. * The index refers to a table of 256 different colours held as normal 8-bit data, but these colours are chosen from a full 24-bit palette (i.e. from 16.8 million different colours). A given pixel's colour is then defined by its position or index in the table (also 'colour look up table'). * It is a compact way to store colour information, but can led to problems when tables of different systems fail to match up. * Particularly useful when colour range is not wide yet must be accurately reproduced e.g. silk-screen printing on packaging or for Web pages.

Related Terms: CLUT

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