Cindy,
I always believe you should wear what you feel best in. On my recent PG cruise I wore a number of dresses similar to the ones Karen posted pictures of. I did wear one dressy one on my anniversary and was certainly more dressy than anyone else, but I didn't mind. Some wore long dresses on Christmas but nothing in velvet. It is cool in the dining room so I always make sure and have a shawl or pashmina. I think Wendy is right is saying that it is more tropical, but again you should wear what you want. No one will say a word or think anything about it.