Not every suggestion, just I saw you dismiss some other interesting concepts that could have worked.
Anywho, another powder game called Dust has an explosive called fireworks. When you create fireworks, whatever was on the right selection the fireworks would explode into that element. If we do that, as tutut125 says, it would work just fine.
Every concept ''could have worked'' it's just that the things that I think is not useful for ME, I say that, if I think I would use it, I say it, that's how we find the most intresting and useful things.