Women are depicted as white on Greek pottery and referred to as white in Greek poetry for the obvious reason that women have lighter skin than men do.

The sea is something completely different, and the darkness isn't a power reference anyway. Men are not called "dark" because they're stronger than women; they're called that because they're darker than women. And, as the article notes, the sea isn't called "dark" at all. "Dark" was a suggestion introduced in the 19th century by the standard classical Greek dictionary.