Determination of the color of petroleum products is used
mainly for manufacturing control purposes and is an important
quality characteristic, since color is readily observed by the
user of the product. In some cases, the color may serve as an
indication of the degree of refinement of the material. When the
color range of a particular product is known, a variation outside
the established range may indicate possible contamination with
another product. However, color is not always a reliable guide
to product quality and should not be used indiscriminately in
product specifications.