Usually , cocktail dresses display shorter length than usual gowns and they are often brighter color and fashion design , aside , and they are normally worn during informal cocktail parties . Even though cocktail gowns look chic and casual , sometimes , they can also be ideal to be utilized for more formal occasions . Current cocktail dresses in the market are in a huge variety of styles , designs , shapes and lengths . With the cocktail party increasing , the fashion cocktail dresses are more and more popular .