A black tie dress code is typically stated for events that occur after 6 P.M. This type of dress code is used for social events that sometimes include dinner and dancing. Traditionally, women wore a formal or tea length sleeveless dress, often with a wrap or stole, gloves, and evening shoes. In these modern times, a cocktail dress is equally appropriate, but it must not be too short. You may also wear whatever type of sleeve you choose. Long sleeves are nice in the winter, but a nice strapless works year-round. Gloves are no longer necessary unless you are going to the opera. A wrap or stole is also not necessary, but is generally a good idea in case you get chilled.
Remember, just because the invitation states black tie, it does not mean you must wear black. Show your personality through color choices. However, keep in mind the formality of the event and the season in which it occurs when choosing color.
The gold dress below works perfectly for a New Year’s Eve event or any semi-formal black tie. The red is great for those who like color and want to stand out amidst the sea of black.
Sources: Emily Post, Debretts, Wikipedia