The charcoal in the gunpowder mixture behaves like a black body. As the charcoal is heated to sufficiently high temperatures, it glows with a faint red color. As it is heated further, the colors change from dark red to bright red to orange to yellow to white. By then it is radiating photons with all the wavelengths that our eyes can see. For materials like charcoal, incandescence occurs from about 480^oC to about 1400^oC (896-2552°F).

Other metallic fuels, such as aluminium (3500^oC/6332°F), magnesium (3200^oC/5792°F) and titanium (2900^oC/5252°F), achieve high levels of brightness when burned, so can be used to make the bright sparks that are given out by many fireworks.

How are fireworks made? 

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