The flames in this video were created and captured by Gavin Free and Daniel Gruchy, also known as The Slo Mo Guys. They used Tiki Oil to produced the different colored flames (Start at 2:14). The Oil was poured into spray bottles to be propelled into a flame and combust. This video captures flow visualization from both art in science lenses through using different kind of chemicals such as Sodium Borate, Copper Chloride, Potassium Sulfate, etc., to produce these vibrant and colorful flames. Fires and combustion are some of my favorite things to watch flow, especially through the lens of a slow motion camera to see how beautiful and intricate flames can be.
Credit: Gavin Free & Daniel Gruchy