How do I read the color of a spark plug? Look at the firing tip of your spark plug while paying close attention to the condition and color of the ceramic insulator and the metal electrode. Observe the color first. Light tan or gray deposits are normal, and an indication that everything is working well.
Definition of candle. 1  1 : a usually molded or dipped mass of wax or tallow containing a wick that may be burned (as to give light, heat, or scent or for celebration or votive purposes) 2  2 : something resembling a candle in shape or use a sulfur candle for fumigating.
A candle is a tool for slowly vaporizing and burning wax. As they heat up, the rising carbon atoms (as well as atoms of other material) emit light. This heat produces light effect is called incandescence, and it is the same kind of thing that creates light in a light bulb. It is what causes the visible flame.Flame color varies depending on what you're burning and how hot it is. Color variation within in a flame is caused by uneven temperature.his heat produces light effect is called incandescence, and it is the same kind of thing that creates light in a light bulb. It is what causes the visible flame. Flame color varies depending on what you're burning and how hot it is. Color variation within in a flame is caused by uneven temperature.