Gender reveal with powder: how?

Question

We bought the kit for our gender reveal to shoot a target with colored powder. 
Apparently, we can’t legally shoot the gun needed to make it explode in our back yard. (Has to be 500 yards away from a house in our area) 
Now I have 2 lbs of tannerite and 15 lbs of blue chalk. Any ideas on how to make an exploding bomb or something to that effect for our party??? 
Thanks!

Answer

Find public shooting grounds. We did ours at a range with permission from the owner of course!

Answer

did mine with a bb gun

Answer

I've never messed with tannerite before but could you do a firework or would a metal pellet and pellet gun be enough to set it off?

Answer

go to a friend or family members home