TODAY'S SCIENCE TRIVIA: Fireworks have been around for centuries, and while pyrotechnics experts have used variations of the same basic components to get different hues, the perfectly deep, bright version of one particular hue remains a mystery: blue.
Creating fireworks requires putting together an oxygen-rich chemical (an oxidizer) and a fuel source such as charcoal-based black powder. As the fireworks shell reaches a certain height after launch, a chemical reaction takes place, at a temperature above the standard boiling point. When the oxidizer and fuel mix, the product is heat—and a colorful explosion in the sky.
A typical fireworks shell can contain up to eight colors, determined by the oxidizers you use. Strontium compounds, for instance, generate red, sodium produces yellow or gold, and potassium produces purple.
It's not that easy to find the right combination of metals for the perfect color, though. In fact, experts say that you can only really accomplish this through trial and error.
Furthermore, as the flame gets hotter, the colors become brighter; at a certain temperature, however, the metal emitting the color is destroyed, resulting in a rather muted color.
This becomes particularly challenging if you want to create blue fireworks. Aside from the fact that blue just tends to blend in with the darkness of the evening sky, the metal necessary for the blue hue, copper, is easily destroyed at high temperatures. As a result, blue always pales in comparison to the other colors, fading away rather quickly.
