PFN_COLOR_COUNT

   (Alpha and Integrity servers) PFN_COLOR_COUNT specifies the
   number of buckets (colors) into which all members of the zeroed
   page list and all unencumbered members of the free page list are
   sorted. OpenVMS Alpha systems might derive a preferred page color
   from a request to map a given virtual page and attempt to map
   that virtual page to a PFN of matching "color." This results in
   less variance in which cache blocks are used when accessing that
   page. This might or might not improve performance, depending on
   the application.

   This special parameter is use by VSI and is subject to change.
   Do not change this parameter unless VSI recommends that you do so.
   If you increase this parameter, you must also increase the ZERO_
   LIST_HI system parameter.