Fashion help sought

OK, so I'm clueless on a lot of girly-type things such as fashion and makeup and all that (me? I had a dress code all through high school and spent college wearing something resembling jeans-and-t-shirts). And tonight MAB and I are dressing up all formal-like, which we do periodically but rarely. So I have a question for anyone who might be able to help:

My outfit for tonight is black velvet skirt-black velvet blouse-and-jacket combo, fancy-shmancy shoes. Do I need black nylons? Or are my standard tan-colored ones OK?

I know this sounds like a silly question to a lot of people...but these are the things I worry about sometimes.