I never got to have my party like I wanted to, but I did end up making cupcakes.
I used mutal colors for the frosting and on the inside of the cupcakes I put the correct gender colored frosting.
The paint fight is such a cute idea and is what I wanted to do!
Best way to find some ideas also is go on pingtrest!
I've seen people do it with a cake. .... You make the cake either pink or blue on the inside so when you cut into it you find out.. And that way you can just give the envelope to the cake maker, tell them what to do, and you get to be surprised too!! Good luck