Slip dresses have a wide variety of colors and design patterns. Slip dresses are made to resemble a silky night gown or any other under garment. They are usually smooth material dresses with a lace trim and they hug the body. These dresses can be mistaken as pajamas so make sure if you get one, get a one that is obviously a real dress and accessorize it well to distract from the jammie look. Don't over accessorize because these dresses tend to be fancy as is.