Sorry for the delayed reply. Anyways, it's not just that Sim in particular, but every vampire Sim in the neighborhood I'm playing in. Here's a screenshot of another Sim, but from the same neighbourhood (just woke up and was too lazy to load up Sims for a pic):
Samoht04, his eyes were dark brown, but I used contacts so that they're light blue. All the vampires in the town are like that, so I doubt it has to do with eye colour, sadly.
The sweetest pea and pallyndrome, I have no idea about the being born w/ a tattoo thing. All I know is that fangs and tatts are automatically applied...on mine at least.