Add a color map menu to the current figure.
Each of the menu choices operates on the colormap:
HOT , PINK , COOL , BONE , JET , COPPER , FLAG and PRISM are names of
functions which generate color maps.
RAND is a random color map.
BRIGHTEN increases the brightness.
DARKEN decreases the brightness.
FLIPUD inverts the order of the colormap entries.
FLIPLR interchanges the red and blue components.
PERMUTE cyclic permuations: red -> blue, blue -> green, green -> red.
SPIN spins the colormap, which is a rapid sequence of FLIPUD 's.
REMEMBER pushes a copy of the current color map onto a stack.
RESTORE pops a map from the stack (initially, the stack contains the
map in use when COLORMENU was invoked.)