He's kind of curious when he sees the red hair. Is there something about that particular color of hair that makes you especially annoying? There was Nancy Bobofit first. She was awful. Now, of course, there's her. Rachel Elizabeth Dare. He's met her once, and already he's strangely annoyed by her. Yeah, maybe it's the fact that they're redheaded. It must make them extremely maddening. Sure, Rachel hasn't been all that rude (if anything it's him), but he certainly doesn't have a good first impression. Whether it's the hair color or not, he has the feeling the girl's a nightmare.
AN: Nothing against redheads. It just seems to be a pattern.