NEW YORK — It’s the big day and, of course, finding the right gown is one of the most important decisions for any bride. For fall 2002, designers are offering up more richly detailed looks. That means lots of lace overlays, elaborate beadwork and less traditional colors such as subtle mochas and khakis. And while sleeveless dresses continue to be a strong force, those with sleeves, whether sheer, beaded or satiny, are gaining popularity, as well.