Why do flames change colors?
Coming from the Latin word, flamma, a flame refers to a light emitting, gaseous part of a fire. In the presence of a thin zone, highly exothermic reactions can take place resulting into the production of the visible light. The two main properties of flame are color and temperature. The temperature of flame can be affected by several distinct factors. The factors were identified to be the atmospheric pressure, percentage of oxygen in the atmosphere, the kind of fuel used to initiate flame and the process of oxidation among many others. As studies were continuously studied on the temperature property of flame, it was discovered that cooler flames are depicted by color red and is known to produce the most smoke. With fuel as one of the factors affecting the flame’s temperature, the kind of substance being burnt greatly contributes to such temperature as well.
On the color property of flames, it, too, is affected by a variety of factors. One of the most important factors being identified was the presence of adequate oxygen supply and the extent of mixture that takes place between the fuel and oxygen. This determines the combustion rate, which is followed by the flame temperature and path of reaction, eventually producing its color hues. The effect that changes the color of flames is similar to the effect that causes light to change color when refracted through certain materials. As the amount of oxygen increases, it also increases the amount of energy used and produced thereby changing the color of the flame being emitted. The colder part of a diffusion, which undergoes incomplete combustion, flame will be red, transitioning to orange, yellow, and white as the temperature increases.
Therefore, the change in flame’s color indicates a change in reactions taking place.