RocketScience!

Colors

The story of fireworks' colors begins with something much, much, much smaller: electrons. Tiny bits of energy whirling around the atoms that make up, well, everything. Rather like guitar strings know their notes, electrons know their energies; they can only whirl so fast and so far. They just won't whirl any other way, unless we give them extra energy. Then they can follow new rules, whirling faster and farther than before!

The cool stuff happens when we play with the electrons. We can give them extra energy, let the electrons get excited, and wait for them to throw that energy back. Sometimes what we get back is completely different. If you get stuff hot, some of that heat comes out as light. If you put electricity through a neon sign, it glows pink. Your clothes can take light and turn it into heat: that's why black shirts get hot in the sun. A solar cell can even turn light into electricity!

What does this all have to do with fireworks? Well, if we pick the right atoms, then their electrons will "play the right notes" or really they will give off the right amounts of energy. Different amounts of energy make different colors of light. For instance, the sodium in salt glows a bright yellow when its electrons give off energy.

Here are some of the different metals and the colors they make when they get very hot.
Color Metal
Red Carmine: Lithium compounds. Masked by barium or sodium.
Scarlet or Crimson: Strontium compounds. Masked by barium.
Yellow-Red: Calcium compounds. Masked by barium.
Yellow Sodium compounds, even in trace amounts. A yellow flame is not indicative of sodium unless it persists and is not intensified by addition of 1% NaCl to the dry compound.
White White-Green: Zinc
Green Emerald: Copper compounds, other than halides. Thallium.
Blue-Green: Phosphates, when moistened with H2SO4 or B2O3.
Faint Green: Antimony and NH4 compounds.
Yellow-Green: Barium, molybdenum.
Blue Azure: Lead, selenium, bismuth, CuCl2 and other copper compounds moistened with hydrochloric acid.
Light Blue: Arsenic and come of its compounds.
Greenish Blue: CuBr2, antimony
Violet Potassium compounds other than borates, phosphates, and silicates. Masked by sodium or lithium.
Purple-Red: Potassium, rubudium, and/or cesium in the presence of sodium when viewed through a blue glass.

 

Curious? You can Try It at home!
Make your own colors!

Next learn about what
gives fireworks different shapes.

Then put it all together and
build your own fireworks online!

Or go back to the introduction.