The very complicated hairstyles for women in ancient Rome, didn't really arrive until the era of the Flavian emperors, after AD 69. Until then the hairstyles were pretty simple, with the hair being parted in the middle, then pulled back and tied up into a bun. Small ornaments were sometimes placed in the hair, depending on the occasion.
As most Roman women had dark Mediterranean looks, fair hair was widely admired and coveted and therefore substances to lighten the hair were extremely popular. The most commonly used of these were Batavian foam and soap tablets from Wiesbaden or Mainz - made of goat fat and beechwood ash. They also used henna.