Obvious appearance with red eyes and fangs, ignored by every single NPC in the world.
Yeah he often smiles widely, revealing his fangs in the process.
But maybe people think
"this is just how Elves are" when they see him?
Ignorance plays a big part in such medieval world I guess. Do not forget it does not matter if people know Vampires exist.
Most who "meet" them will not live to tell the tale.
Albino's are a rarity in our own world. Aka very pale coloration and red or light-red eyes.
But so what. I bet people are more concerned about a regular Tiefling as some other random Humanoid with a more unusual coloration.
Vampires are also supposed to not exist in the sunlight.
Suggestive logic can play a big role in making a false evaluation or judgement.
Even that Vampire-hunter dude does not considered Astarion the Vampirespawn he hunts, when he is confronted by him
in the daylight.
