void color_area(int start, int end, char *colorname)
Colors text region from position start to position
end with color colorname (see the standard X11 file
rgb.txt). This function can be used with the regexp
interface to color strings of your own modes (see
color.sc §5.11 page ).
Removes all colors in the current buffer.
Returns 1 if your display is monochrome, else 0.