Complex sentence: The term "sultana" is not commonly used to refer to any type of raisin in American English; as most American raisins are from sultana grapes, they are called simply "raisins" or "golden raisins," according to colour.
Split into simpler sentences: The term "sultana" does not commonly refer to any type of raisin in American English. Since most American raisins are from sultana grapes, they are called simply "raisins" or "golden raisins," according to colour.