From the ArcaMax Publishing, Wedding Guide Newsletter:
http://www.arcamax.com/news/weddings/s-26791-299037
At weddings, it seems that everything centers on the bride's attire.
Follow these simple rules to make sure you have the perfect attire for
your big day.
For formal weddings, it is customary to wear a long white or off-white
dress. The dress may be shorter for semi-formal ceremonies, though.
Whatever the bride wears, the bridesmaids should be matched
accordingly - the formality of her dress will dictate how formally the
rest of the wedding party should be dressed.
If the wedding ceremony is to take place after 6 PM, the wedding tends
to be more formal. This may not change the cut of the bride's dress,
but should dictate the sort of fabric used.
Accessories, too, are dictated by the style of gown. If the dress is
short-sleeved, long gloves should be worn; if it is long-sleeved,
gloves may be worn at the bride's discretion. The bride's shoes
should also match the gown. A long veil should be worn attached to a
headpiece, such as a tiara. And don't forget the blue garter under
the gown!