How do you explain the colors in fireworks scientifically? It's all about chemicals inside of them! Every time a new color pops up, it's the result of a chemical reaction producing colors. White comes from white hot metal flakes, red array, are from strontium carbonate, for example.

Here's the complete list of the chemical cocktails that go into different fireworks, courtesy of The Works Museum in Bloomington, Minnesota:
[The Works via BoingBoing]