Candle Flame Color
Here are some approximate temperatures for the different parts of a candle and its flame. Note that the exact temperatures vary quite a bit depending on all kinds of different factors, notably the type of wax from which the candle is made but also the ambient (air) temperature, and how much oxygen is present. Please don’t take these values as absolutely definitive ones that apply in all cases—they’re just a rough guide.
Wick: 400°C (750°F).
Blue/white outer edge of the flame (and also the blue cone underneath flame where the oxygen enters): 1400°C (2550°F).
Yellow central region of the brightest part of the flame: 1200°C (2190°F).
Dark brown/red inner part of the flame: 1000°C (1830°F).
Red/orange inner part of the flame: 800°C (1470°F).
Body of the candle: 40-50°C (104-122°F).
Melted pool of wax on top of the candle: 60°C (140°F).
Perhaps surprisingly, the brightest part of the flame is not the hottest. The blazing part of the flame gives off three quarters of its energy as light and only a quarter as heat (so you can see a candle is, at best, around 75 percent efficient as a lamp).
The hottest parts of a candle flame are actually the blue, almost invisible area near the base, where oxygen is drawn in, and the blue/white part around the edge, where the flame meets the oxygen-rich air all around it. The flame gets progressively cooler as you move in from the outside edge toward the wick. Cooler areas are darker and colored orange, red, or brown. Most of the flame’s heat is delivered toward the tip, where a large volume of gas is always burning and convection is sweeping hot gases constantly upwards. If you want to heat something with a candle, hold it near the tip.