The perception of color in organic and inorganic artists' pigments (e.g. earth color type, iron blue, ultramarine, hansa and cadmium yellow pigments) is related to such physical properties as lightfastness and brilliance. Included in the discussion are the nature of color, the types of chemical species exhibiting color, and their structural features. Compounds are categorized according to the structural properties that enable them to absorb visible radiation. -- AATA