Posting this for archival purposes, it's a variation of funfare' script but it randomizes colors between 2 and 15, skipping 0 and 1 (white and black).

Modified by maroon for me on ##mirc freenode.

Code:
on ^*:TEXT:*:# { 
  var %col $calc(($base($left($md5($nick),13),16,10) % 14) +2)
  echo -t $chan < $+ $chr(3) $+ %col $+ $nick($chan,$nick).pnick $+ $chr(3) $+ > $1- 
  halt
}