Subject:   -59- Why does nothing happen when I call mapcolor(index, R,
                G, B)?
Date: 07 May 1993 00:00:01 EST

  You either need to call glcompat(GLC_SLOWMAPCOLORS, TRUE) at the
  beginning of your program, or call gflush() after calling mapcolor.

  See the NOTES section in "man mapcolors" and also "man glcompat" for
  further info. (This may also be in the GL release notes)