You basically pick a tribe for the appearance of your generation and the previous.
The Romans resemble spartans. They wear white kilts, golden breastplates, and males wear red-feathered helmets. Female Romans have black Cleopatra hair.
The Teutons resemble peasants. They wear brown shirts, darker brown pants and males have huge red hair and beards. Female Teutons have metal headbands holding up their ponytails.
The Gauls resemble waiters or taverners. They wear green shirts, yellow pants, and males wear steel viking helmets. Female Gauls have blonde pigtails.