I think it's your wedding and you can chooose whatever colors you like ! Whocares if it's a destination wedding. I have seen all colors of the rainbow done at destination weddings. If you love those colors , I think you may regret not using them. This day only happens once so how you envision it as perfect is solely your choice!!
I am choosing a black and white theme - with a splash of Red. My groomsmen will be wearing black pants and white long sleeved shirts. My fiance will be wearing the same with a black tie ( still debating on the jacket) All of my favors and decorations will be black/white and my Bridesmaid dresses are Cherry Red. I picked Red for my dresses because I have always loved red, I have also had a few people tell me that perhaps I should change my color because I am getting married on a beach, but it's my wedding and that's just how it's going to be !
I wanted to keep it simple. Let us know what you decide!!