Gender reveal idea help!

Meg • New York City first time mom!
Hi friends!   So I want to do a gender reveal party in a few weeks and I'm looking for ideas on how to reveal the gender. I originally wanted to do a powder paint fight because I wanted everyone to be involved, but I think it's going to be too messy for the event place.   Any ideas for a fun / all inclusive/ non-messy gender reveal?   I love the thought of silly string but in pictures I see the color is not very vibrant. 
Thanks for your help!