LisBott

We are going on our first RC cruise. We are going on a 4 night cruise on Brilliance of the Seas and heard there are theme nights on RC Cruise ships... Will we get advance notice? Heading to Cozumel in Feb 2017. TIA

No, those kinds of ship-specific events are not advertised before the sailing...but they will be advertised once onboard - in the Compass.
 
There are typically white out events, 70's or 80's street parties and if your sailing has the Prohibition Party (paid event) then you might want to dress up for that.  Generally, that's about all you will see.

There is a white out night on the Adventure of the Seas.  It's not a big deal.  RCCL never puts anything out on it in advance.  Very few people are involved.  It happens too late at night for us.  I hope this helps.