Ah, you're right, it was a mistake on my part, which is easily fixed though:
Code:
alias repalltok { 
  var %i = $findtok($1,$2,0,$4), %a = $1 
  while %i {
    %a = $reptok(%a,$2,$3,[color:red]%i[/color],$4)
    dec %i
  } 
  return %a
}
Here's another alternative that doesn't use loops at all (which makes it faster if the string contains many replaceable tokens)
Code:
alias repalltok2 {
  var %x = \x $+ $base($4,10,16,2)
  !.echo -q $regsub($gettok($1,1-,$4),/(?<=^| %x )\Q $+ $&
    $replacexcs($2,\E,\E\\E\Q) $+ \E(?=$| %x )/gix,$replace($3,\,\\,$,\$),%x)
  return %x
}