type /zz to initiate the rainbow creation. warning, this fills tons of memory. it may take more than a minute to generate this wicked rainbow.

alias zz { 
  window -paxdk0 @funbox 
  unset %fail %cow 
  while %fail != 50 { 
    inc %fail .1
    unset %cow 
    while %cow != 50 { 
      inc %cow .1
      drawdot -r @funbox $hsv($calc(%fail * %cow ),1,150) 1 $calc(%cow *10) $calc(%fail *10)
    } 
  } 
}
;$hsv by DukeNukem
alias -l hsv {   
  var %h $$1,%s $$2,%v $$3,%hi $calc($int($calc(%h / 60)) % 6),%f $calc(%h / 60 - %hi),%p $calc(%v * (1 - %s)),%q $calc(%v * (1 - %f * %s)),%t $calc(%v * (1 - (1 - %f) * %s))  
  if (%hi = 0) { var %r %v,%g %t,%b %p } 
  if (%hi = 1) { var %r %q,%g %v,%b %p }  
  if (%hi = 2) { var %r %p,%g %v,%b %t } 
  if (%hi = 3) { var %r %p,%g %q,%b %v }  
  if (%hi = 4) { var %r %t,%g %p,%b %v } 
  if (%hi = 5) { var %r %v,%g %p,%b %q }
  var %r $int($calc(%r * 255)),%g $int($calc(%g * 255)),%b $int($calc(%b * 255)) 
  return $rgb(%r, %g ,%b)
}