This directory, /usr/graphics/ctable, contains the color tables we
use with Red, Green, Blue values identified from 0 - 32767. These
are ASCII files which can be changed to create color schemes of your
choice.  The file, fcolor, is the one which is used most of the time.
If you look at any of the /usr/graphics/testplots c sources, you will
notice that fcolor is the file used to load the color map.  The file,
grayscale, is used for gray scale.  You can change these files, or leave
them as they are, or create one of your own.
