I also went more relaxed on the food and loosely followed the theme. Everything except fruit was in individual cups so you could just grab and go.
Chocolate and rainbow sprinkle pretzel sticks
7 layer dip
Lucky Charms (the kids said "Look! Rainbow cereal! How could I resist?)
Mini waters wrapped in scrapbook paper and mini sodas
My little girl felt totally special and ooohed and ahhhed over every detail. I'd call that a success!