The appearance of manufactured product, assuming that it fulfills its principal function, is its most important attribute, influences its marketability. Of all the visual aspects, color is perhaps the most important to the observer. A poor color or a variation in color in a given batch of product is perceived as being a sign of poor quality. The appearance and color, therefore, constitutes the essential message of the product. The three elements influencing this are the Light Source. The Object. The Observer.

Colorimetry tries to translate the visual judgment of the human observer into objective values, in color vision, the visual sensation interprets the impression of color on the basis of: