It is a common misconception that a flame is hotter on the outside. In reality, the hottest part of a flame is actually in the center.
The outside of a flame appears to be hotter because it is where the combustion is happening and where most of the visible light is emitted. However, the temperature in this area is actually lower than the center of the flame.
The difference in temperature between the center and the outside of a flame is due to the distribution of fuel and oxygen. The center of the flame has a higher concentration of fuel, while the outside has more oxygen. This creates a temperature gradient, with the center being hotter and the outside being cooler.
In most cases, the outside of a flame will never be hotter than the center. However, there are certain conditions where this can occur, such as when the flame is blown by strong winds or when there is a lack of oxygen in the center of the flame.
Yes, the temperature of a flame does affect its color. The hotter the flame, the more energy is emitted as light, resulting in a brighter and bluer color. Cooler flames will emit more red and orange light.