Andrea's everyday outfit is a pale green formal dress. Even though she has black hair, her natural hair color is actually blonde. Like all townies in The Sims 2, Andrea's career, skills and relationships with other townies are usually randomized at the start of the game.
She seems to be of a mixed heritage, having Asian facial features, dark skin and green eyes. She has the same facial structure as Marie Deppiesse from Bluewater Village.
↑This page (in French) shows the genetic skintone, hair color, and eye color for most of the townies and NPCs in Pleasantview. (Original link is dead; link is to archived version; note that not all the information is correct which can be proven with SimPE.)