It used to be that when women dressed up, they carried small black, beige or white handbags. Not anymore. Exotic designs, daring colors and vivid prints give today's evening bags a new savoir-faire. Fabric treatments are imaginative--silk combined with rubber, satin adorned with metallic appliques, leather juxtaposed with pearls. Shapes, too, cover a creative gamut. Minaudiere-influenced bags are shaped like apples, pears and shells. Circle bags have wrist straps, and mini-totes come with an old-fashioned handle. And then there are pouches, oblongs, square clutches and tiny, metal lunchboxes.