SetRGBPalette procedure

  DECLARATION:  SetRGBPalette(ColorNum, RedValue,
                              GreenValue, BlueValue : Integer);

      PURPOSE:  Changes palette for VGA and IBM-8514 drivers

         UNIT:  Graph

      REMARKS:  ColorNum defines the palette to be loaded and RedValue,
                GreenValue and BlueValue define the individual colors of
                the palette entry.

                The valid range for ColorNum, for the VGA in 256K color mode,
                is 0..15.  The valid range for ColorNum, for the IBM-8514
                display, is 0..255.

 RESTRICTIONS:  Must first be in graphics mode.
                Only for use with the VGA and IBM-8514 graphic drivers