I'm thinking of big paper pistol targets.  They have shapes, numbers and colors on them.  DI calls "blue, red, 5" and you draw, shoot any blue target, any red target and then the target with a #5 on it.  Or something of that nature.

I can find something like it on Amazon, but it's smaller and 2 color only.

Might get anywhere from 10-25 depending on price.  Links greatly appreciated.

We used to call them DEA Dot Targets (but, that's where we worked, I don't know that everyone called them that).