Narrator: Fireworks have been around for millennia. They flood the sky with brilliant bursts of scarlet, emerald, and ivory. But never blue. Pyrotechnicians have tried to produce blue fireworks ...

Narrator: Fireworks have been around for millennia. They flood the sky with brilliant bursts of scarlet, emerald, and ivory. But never blue. Pyrotechnicians have tried to produce blue fireworks ...

But the invention of colored fireworks is relatively recent ... If you try to make the blue brighter to contrast with the background it can look washed out. The right balance of copper and other ...