Rainbow Fire Halloween Jack-o-Lantern

Easy Multicolored Fire Pumpkin

Halloween jack-o'-lantern, featuring rainbow fire
Halloween jack-o'-lantern, featuring rainbow fire. Anne Helmenstine

Create a spectacular multicolored fire pumpkin for Halloween! This rainbow fire jack-o-lantern is easy to make. 

Rainbow Fire Pumpkin Materials

You only need a few basic materials for this project. The hand sanitizer contains alcohol, which is flammable, but self-extinguishes due to the water in the product. The boric acid or borax provides additional color to the flames.

  • Carved Halloween jack-o-lantern (use a real pumpkin - plastic will melt!)
  • Hand sanitizer
  • Boric acid or borax

What You Do

  1. Smear hand sanitizer all over the outside and inside of the jack-o-lantern.
  2. Dust the pumpkin with boric acid or borax. You don't need very much to achieve a nice colored effect. Just a light sprinkling will suffice,
  3. Ignite the jack-o-lantern.
  4. The flame goes out on its own fairly quickly as the alcohol in the hand sanitizer gets used up, leaving you with water.

How It Works

Boric acid or borax (either works) emit a green light when heated in a flame. The jack-o-lantern gives off a multicolored fire because you have the natural blue of the alcohol flame from the hand sanitizer, the green from the boric acid, orange light coming through the carved pumpkin, plus other colors from where the pumpkin juice mixes with the flame. The pumpkin flesh contains sodium, which imparts a yellow color to the fire.

Tips and Safety

  • You don't have to use boric acid or borax. Try other flame colorants for a different color blend.
  • This is a fire project, so adult supervision is required.
  • Be sure to perform this project on a fire-safe surface.
  • You can extinguish the flame at any time by blowing it out.