Function:    VGAcolor()

               This function makes it possible to change the
               color of a specific color register. It works only
               on VGA adaptors.
               As you may have noted, there are 16 colors to
               choose from when in text mode, whilst the VGA
               can display up to 218 colors. Now one can select
               any of these colors for his text Colors.

               Using this function, One can make nice Fading
               effects, by making everything black, and then
               gently fade in to the actual colors.

  Syntax:      VGAcolor(<Reg>,<RedValue>,<GreenValue>,<BlueValue>)

  Arguments:   <Reg> is the color register to adapt, it must
               be in the range 0..15 (see Colors info for more
               info). The Red, Green and Blue values define the color
               to display. They must be in the range 0..63.

  Returns:     Nothing.

  Usage:       * - See demo programs..
               * - Set black to some random color:
               VGAcolor(0,34,54,12)
               * - Wondering what color this is eh?.. So do I!

  Table:      Here's a table with the VGA default values, and
               the possibilities offered.

  The 16 Standard Colors are defined as Follows:

  Color Number         Color           VGA standard Values:
  (Register)           Name            Red   Green   Blue
  ------------------------------------------------------------
    0                  Black             0       0      0
    1                  Blue              0       0     42
    2                  Green             0      42      0
    3                  Cyan              0      42     42
    4                  Red              42       0      0
    5                  Magenta          42       0     42
    6                  Brown            42      21      0  (*)
    7                  Gray             42      42     42
    8                  LightGray        21      21     21
    9                  LightBlue        21      21     63
   10                  LightGreen       21      63     21
   11                  LightCyan        21      63     63
   12                  LightRed         63      21     21
   13                  LightMagenta     63      21     63
   14                  Yellow           63      63     21
   15                  White            63      63     63
  ------------------------------------------------------------

  (*) I would put "Brown" at 42 42 0, as Brown is really just a
      leftover from the CGA era, and 42 42 0 produces a "Normal"
      yellow, much nicer than an ugly brown.