from
The Free On-line Dictionary of Computing (8 July 2008)
colour palette
CLUT
colour look-up table
palette
<graphics, hardware> (colour look-up table, CLUT) A device
which converts the {logical} colour numbers stored in each
{pixel} of {video} memory into {physical} colours, normally
represented as {RGB} triplets, that can be displayed on the
{monitor}. The palette is simply a block of fast {RAM} which
is addressed by the logical colour and whose output is split
into the red, green and blue levels which drive the actual
display (e.g. {CRT}).
The number of entries (logical colours) in the palette is the
total number of colours which can appear on screen
simultaneously. The width of each entry determines the number
of colours which the palette can be set to produce.
A common example would be a palette of 256 colours
(i.e. addressed by eight-bit pixel values) where each colour
can be chosen from a total of 16.7 million colours (i.e. eight
bits output for each of red, green and blue).
Changes to the palette affect the whole screen at once and can
be used to produce special effects which would be much slower
to produce by updating pixels.
(1997-06-03)