Int 62 Fn 0018  u - Fgdriver V4.02 - "fg_defcolor" - Assign Color Value T  [V]

   AX = 0018h
   BX = color index (0000h-00FFh)
   CX = new color value (0 to maximum color value for current video mode)

Notes: the FGDRIVER functions are rearranged with each major release, but
     their parameters do not change (see #3145)
   This call is ignored in text modes and 256-color graphics modes

See Also: AX=0040h,AX=0045h,AX=00AAh