You need to grab the text from the channel, then use color on it from there..
Code:
on *:TEXT:*:#: {
  haltdef
  if ($nick == bla) { echo $chan < $+ $nick $+ > $+($chr(3),3,$1-) }
  elseif ($nick == test) { echo $chan < $+ $nick $+ > $+($chr(3),4,$1-) }
  else { echo $chan < $+ $nick $+ > $+($chr(3),1,$1-) }
}

But i guess it's a bether way to do it, this is just an idea.