Congratulations on getting cast. There are many different ways to stand out in a chorus. Not all of them are good. Wearing something different may get you noticed right away, but after a few seconds I'd move on to something else. Things that have captured my attention in the past for a good reason are~ being one of the better dancers, whether it's because you are the most technically gifted, or pleasent to watch; staying in character the whole time, giving the appropriate reactions, looking like you want to be there; being just down right too adorable to look away (I'm referring to children that either are just sute as heck, or they remind me of my siblings' kids).
Wearing something flashy will only distract/detract from what you are doing as your character. Remember that you can make your character who ever you want her to be, within reason. When I had my first lead people who didn't know anything about me thought that I had been playing leads for years. I believe that it was because I was always aware of what was going on in my character's mind, by reacting to the situation, even if my character didn't have any lines within that particular scene (which in this show I was practically a deaf mute until scene 7 and then suddenly I was singing and talking like crazy!).
Hope this helps a little