

   RRGGBB CCoolloorr SSppeecciiffiiccaattiioonn

        rgb(red, green, blue, names=NULL)

   DDeessccrriippttiioonn::

        This function creates ``colors'' corresponding to the
        given intensities (between 0 and 1) of the red, green
        and blue primaries.  The names argument may be used to
        provide names for the colors.

        The values returned by `rgb' can be used with a `col='
        specification in graphics functions or in `par'.

   SSeeee AAllssoo::

        `rainbow', `hsv', `gray'.

   EExxaammpplleess::

        rgb(0,1,0)
        u01 <- seq(0,1, length=11); all(rgb(u01,u01,u01) == gray(u01))
        reds <- rgb((0:15)/15, g=0,b=0, names=paste("red",0:15,sep="."))
        reds

