Rules for modern wedding attire have evolved with the times, but there are still traditional standards for fabrics, lengths and styles. Here are some guidelines:
The formality of your bridesmaids’ dresses should match that of your wedding dress. Although traditionally the dresses were the same length as the wedding gown, the rise in popularity of tea- and knee-length bridesmaids’ dresses has relaxed that rule. As long as the fabric and overall style matches the formality of your floor-length gown, shorter bridesmaids’ dresses are perfectly acceptable.
For evening weddings, guests should dress for a nice dinner or event – which includes suits (or black tie) for men and sophisticated dresses or skirts in for women. Lengths can vary according to the style of the event and location. Female guests may now wear black, but never white.
Information found on eleGala.com.