Color theory, or more specifically traditional color theory, is a historical body of knowledge describing the behavior of colors — namely in color mixing, color contrast effects, color harmony, color schemes and color symbolism. Color theory and color science both study color and its existence. Traditional color theory tends to be more subjective and have artistic applications, while color science tends to be more objective and have functional applications, such as in chemistry, astronomy or color reproduction. However, there is much intertwining between the two throughout history, and they tend to aid each other in their own evolutions.