Color is one of the most striking characteristics of everyday life, in large part because the human eye is such a wonderful instrument for perceiving colors. Recent articles in this "Light Touch" column have discussed how white light is actually made up of the full rainbow of colors, and how the colors of light sources can tell us about those sources. So, what does color tell us about flames? For example, candle flames have been around all of us throughout our lives, and we take them for granted as romantic, if not terribly bright, sources of light. But how do candles produce light? And what do the colors of the light they produce tell us?