This is the costume I wore for my ballet preformance. I played an evil fairy and added a nail design to match the wardrobe.
You can use this as inspiration: to match nails and outfits, since I know you do not own the same exact clothes as I do and have different tastes. I just like to keep the colors the same and add whatever feels to fit to the outfit what it may stand for. :P
click here for the tutorial
click here for a more detailed look of the design