Xanthe

This was the name of one of the daughters of the minor Greek god, Oceanus. She was a nephalai nymph who was responsible for yellow tinged clouds. It was also the name of an Amazon and it was borne by the wife of Aesclepius.

In Classical Greece, the name was most likely bestowed upon fair haired girls or used as a sort of nickname for blondes, the equivalent of the English nickname, Blondie, and of the Latin Flavia.

Blonde hair was considered an exotic trait, and was therefore a rarity, yet pertained much admiration. The Greeks considered it as a sign of divinity, in fact, the Greeks liked to believe that the Gods all had blonde hair, especially Aphrodite.

If the idea of an X name is too much to fathom on a child, then you might prefer the slightly more tamed and Italianate Flavia or Flaviana. Xan would make an incredibly spunky nickname option.

Another form is Xanthia and the masculine form is Xanthos (Ξανθος)