rush clothing

It is about you and looking your very best. Stick to colors and styles that flatter you and your figure. Nothing too short or strapless or with spaghetti or bra-type straps, and don't wear solid black. It is HOT and HUMID, so wear fabrics that look good all day and won't wrinkle or droop and lose their shape, or show sweat stains, or will look cheaply made. Make sure you are comfortable and your shoes aren't going to kill you or you will have terrible conversations. Accessorize with thought. Brands and other specifics are not nearly as important as how put together you look. Hair and makeup are very important and need to hold up all day too, with manis and pedis being a must as well. Go with what you like and be you, but be your very, very best you.

Wear what you feel comfortable and confident in (within reason and the guidelines that Panhellenic gives). Show off your personal style, but do it in a way that flatters you and makes you look polished. Like @You! said, it is HOT. You will sweat so much it is not even funny, test our your dresses to make sure they can handle that.
Do things that will make you stand out in a good way, not a bad way (a great way to stand out in a bad way is being very over or under dressed for a round)