I did something similar to the first poster expect with confetti. Me and my finace went to party city and got these black matte balloons so it was like a silvery black (makes it to where you can't see the color of the confetti cause with regular black you can still see through) and we had went to the 99 c store and found pink confetti and just ripped it in pieces prior to filling the balloons. The lady was nice enough to help us stuff it then fill it up with air. You can use a needle, steak knife. Or anything Sharpe to pop it. After you can just vacuum it up!
My brother and his wife filled a black balloon with paint and had it on a board. Family members took turns throwing darts at it till somebody popped it and blue paint went everywhere. I thought it was really fun and creative