Question: Why does fire turn blue or white when extremely hot?

Adam McGuinness answered on 9 Nov 2018:

Wow, good question Edwardso, I didn’t know, so I had a look around on the internet (being able to find out answers to things is a very important skill for a scientist).

From what I read, it seems the yellow colour comes when the flame doesn’t have enough oxygen, so not all of the gas gets burnt. This means you get soot left over (the black stuff that gets left behind on things that have been close to a fire) because this soot gets so hot, it glows yellow, so yellow flame! In blue flames, there’s more oxygen, so more complete burning of the gas, so less soot, no yellow colour!