Science, Tech, Math › Science The Chemistry of Firework Colors What Produces Those Vivid Colors — and the Science Behind It Share Flipboard Email Print Steve Kelley aka mudpig / Getty Images Science Chemistry Physical Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 04, 2019 Creating firework colors is a complex endeavor, requiring considerable art and application of physical science. Excluding propellants or special effects, the points of light ejected from fireworks, termed 'stars', generally require an oxygen-producer, fuel, binder (to keep everything where it needs to be), and color producer. There are two main mechanisms of color production in fireworks, incandescence, and luminescence. Incandescence Incandescence is light produced from heat. Heat causes a substance to become hot and glow, initially emitting infrared, then red, orange, yellow, and white light as it becomes increasingly hotter. When the temperature of a firework is controlled, the glow of components, such as charcoal, can be manipulated to be the desired color (temperature) at the proper time. Metals, such as aluminum, magnesium, and titanium, burn very brightly and are useful for increasing the temperature of the firework. Luminescence Luminescence is light produced using energy sources other than heat. Sometimes luminescence is called 'cold light' because it can occur at room temperature and cooler temperatures. To produce luminescence, energy is absorbed by an electron of an atom or molecule, causing it to become excited, but unstable. The energy is supplied by the heat of the burning firework. When the electron returns to a lower energy state the energy is released in the form of a photon (light). The energy of the photon determines its wavelength or color. In some cases, the salts needed to produce the desired color are unstable. Barium chloride (green) is unstable at room temperatures, so barium must be combined with a more stable compound (e.g., chlorinated rubber). In this case, the chlorine is released in the heat of the burning of the pyrotechnic composition, to then form barium chloride and produce the green color. Copper chloride (blue), on the other hand, is unstable at high temperatures, so the firework cannot get too hot, yet must be bright enough to be seen. Quality of Firework Ingredients Pure colors require pure ingredients. Even trace amounts of sodium impurities (yellow-orange) are sufficient to overpower or alter other colors. A careful formulation is required so that too much smoke or residue doesn't mask the color. With fireworks, as with other things, cost often relates to quality. The skill of the manufacturer and date the firework was produced greatly affect the final display (or lack thereof). Table of Firework Colorants Color Compound Red strontium salts, lithium salts lithium carbonate, Li2CO3 = red strontium carbonate, SrCO3 = bright red Orange calcium salts calcium chloride, CaCl2 calcium sulfate, CaSO4·xH2O, where x = 0,2,3,5 Gold incandescence of iron (with carbon), charcoal, or lampblack Yellow sodium compounds sodium nitrate, NaNO3 cryolite, Na3AlF6 Electric White white-hot metal, such as magnesium or aluminum barium oxide, BaO Green barium compounds + chlorine producer barium chloride, BaCl+ = bright green Blue copper compounds + chlorine producer copper acetoarsenite (Paris Green), Cu3As2O3Cu(C2H3O2)2 = blue copper (I) chloride, CuCl = turquoise blue Purple mixture of strontium (red) and copper (blue) compounds Silver burning aluminum, titanium, or magnesium powder or flakes Sequence of Events Just packing colorant chemicals into an explosive charge would produce an unsatisfying firework! There's a sequence of events leading to a beautiful, colorful display. Lighting the fuse ignites the lift charge, which propels the firework into the sky. The lift charge can be black powder or one of the modern propellants. This charge burns in a confined space, pushing itself upward as hot gas is forced through a narrow opening. The fuse continues to burn on a time delay to reach the interior of the shell. The shell is packed with stars that contain packets of metal salts and combustible material. When the fuse reaches the star, the firework is high above the crowd. The star blows apart, forming glowing colors through a combination of incandescent heat and emission luminescence. Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "The Chemistry of Firework Colors." ThoughtCo, Feb. 16, 2021, thoughtco.com/chemistry-of-firework-colors-607341. Helmenstine, Anne Marie, Ph.D. (2021, February 16). The Chemistry of Firework Colors. Retrieved from https://www.thoughtco.com/chemistry-of-firework-colors-607341 Helmenstine, Anne Marie, Ph.D. "The Chemistry of Firework Colors." ThoughtCo. https://www.thoughtco.com/chemistry-of-firework-colors-607341 (accessed September 26, 2021). copy citation The Science Behind Firecrackers and Sparklers Pigment Definition and Chemistry Chemical Elements in Fireworks List of Halogens (Element Groups) 10 Amazing Chemical Reactions What Is Chemiluminescence? 10 Cool Chemistry Experiments Phosphorescence Definition and Examples Chemical Element Pictures - Photo Gallery How to Make a Roman Candle Firework How Glow in the Dark Stuff Works Ultimate Colored Smoke Bomb Gunpowder Facts and History Why Is Fire Hot? How Hot Is It? Calcium Facts - Ca or Atomic Number 20 What are Hypergiant Stars Like?