Black Tie

* For men, black-tie denotes a single or double-breasted dinner jacket with a black silk bow tie (properly referred to as a dinner jacket, but commonly called "tuxedo" or "tux.").
* For women, an invitation to a black tie event means wearing a long, floor length evening dresses or evening separates. A short cocktail dress may be appropriate for some cocktail receptions, summer events, or daytime functions.

It doesn't have to black but it definitely should not be white