I made this iPhone app primarily to annoy a friend of mine who is colour blind, but it could also be used as an educational tool, for parents to test their kids

I made this iPhone app primarily to annoy a friend of mine who is colour blind, but it could also be used as an educational tool, for parents to test their kids etc I'd love to get any feedback / ideas / comments (both on the app, and whether I'm crazy to position it as a tool to annoy people)