We just returned from our 1st cruise. My husband wore a dark gray/blue suit for the formal and informal night and I had a couple cocktail dresses. I was worried that we wouldn't be as formal as we should be. My advice to you is to NOT WORRY ABOUT IT. On our formal nights, men and women were dressed all over the board. Some were really formal (gowns) and others had light color suits/dresses. I worried too much about it. Enjoy the cruise!