Color / Colour Palettes
GIF images include color palettes, or predefined sets of as many as
256 colors, which define which colors they will use.
There are two types of palettes --
an adaptive palette, using the colors already in the image,
or a system palette, using a computer platform's preset group
of 256 colors.
Adaptive palettes usually give the best results when the image is
viewed on a monitor that has thousands or millions of colors.
Netscape navigator (and many other application programs) has a
pre-defined set of colors, or color table
that it uses to display images in HTML pages.
If a color used in an image is not found in the color table,
the software will either substitute a color from the color table
which is similar to the color specified in the image,
or it will dither the colors to approximate the desired color.
A color which is "dithered" will appear to be made up of pixels of
two colors, which blend together visually to approximate the desired
color.
Here is a simple Perl script to generate the
the 6x6x6 color map.
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