Are you in some form of management? I would think slacks would be the more professional option. But if you are just a regular associate jeans are fine. But if you are in a dept. where you are often getting your clothes dirty, such as working with food. Then I don't think black would be a good color choice unless you know a secret to NOT getting a bunch of crumbs and other fun things on ya.
at my store it's supposedly khakis or jeans that are dark blue/black, but i've seen some girls wearing red jeans before on the regular and they don't get chewed out. are you allowed to wear shorts this time of year? CCs at my store are allowed to wear shorts from the beginning of june until labor day.