Date: 07 May 1993 00:00:01 EST

  By default, the SGI X Server is configured to use an 8-bit
  PseudoColor visual.  X-based applications can request other visuals
  directly if they are available.  Alternatively, you can change the
  default visual by performing the following steps:

  a) Run "/usr/bin/X11/xdpyinfo" and check that your server is
     capable of using a 12-bit or 24-bit visual.  If it is,
     you will see lines similar to the following:

     visual id, max buffers, depth:    0x28, 0, 12
     visual id, max buffers, depth:    0x29, 0, 12
     visual id, max buffers, depth:    0x2a, 0, 24

     The last number on each line represents the number of bits
     available for that visual.

  b) Log in as root

  c) Edit the file /usr/lib/X11/xdm/Xservers.  By default it
     will contain the string:
       :0 secure /usr/bin/X11/X -bs -c -pseudomap 4sight
     for a 24-bit TrueColor visual change it to:
       :0 secure /usr/bin/X11/X -bs -c -class TrueColor -depth 24
     for a 12-bit PseudoColor visual change it to:
       :0 secure /usr/bin/X11/X -bs -c -class PseudoColor -depth 12

  d) Restart your X server as above.

  Note:  X Server visuals are an advanced topic; before making the
  above changes you should be aware that some 3rd-party and freeware
  applications might not gracefully adapt to an X Server which supplies
  anything but an 8-bit PseudoColor visual by default.