The big dress dilemma!

In January we'll be in Salvador, Brasil, for Y's wedding. Finding the appropriate dress has been an absolute nightmare, but I've now found two! The trouble is, I can't decide between them! So I'm going to ask you!

In Brasil people apparently tend to dress up quite a lot for weddings. This one starts at about 5:30 and the expected heat will be about 40 degrees. However, I'm not exactly one for standing out in the crowd - especially when that crowd and I don't speak the same language.

Answers on a postcard please!