The colors will be purer if you use ethanol (denatured alcohol, 190 proof Everclear or equivalent) as fuel. High concentration isopropyl alcohol has a yellow ti

The colors will be purer if you use ethanol (denatured alcohol, 190 proof Everclear or equivalent) as fuel. High concentration isopropyl alcohol has a yellow tinge to the flame from soot formation. Methanol (sold to the public in the US in convenient small bottles as Heet Gas-Line Antifreeze) is also very good and may be easier to obtain in some areas than pure high-proof ethanol. Sodium chloride, lithium chloride, copper chloride, and boric acid give the most intense colors. But sodium chloride's orange-yellow color is a bit boring compared to the others. A few milliliters of the alcohol mixture can be ignited in a shallow stainless steel dish with relative safety and there will be no color interference from carbonaceous fuels yellowing the flame via soot. If I had to pick just one to try, I'd suggest boric acid. The green flames it produces are unlike any "ordinary" fire and boric acid is easy to find. Here's a short video with a good view of how the flames look: https://www.youtube.com/watch?v=g1jHVk6oqjU https://www.youtube.com/watch?v=g1jHVk6oqjU The first night that my now-wife met me in person, I showed her colored fire like this in the fire pit at my apartment complex. She originally meant to visit for just a few days but we've now spent 21 years together. I'd say that the demonstration was a success.