You shoul've received an email with the cruise guide, it's all listed there.
Buther it is:
Yes there 3 theme nights
1. Formal Night - dress to impress
2. White Party - don your whitest whites and lets light up the caribbean sky
3. 70's Party - let's take it back to the decade when olivia was born
Also the theme day - "Show us your roots"! wear a t- shirt or hat that represents your home town