An important property of ceramics is the color. This pertains to the fragment as well as to the coating and the over-painting. The fragment-colors are of special interest when examining the firing procedure. The goal is to gain cultural and historical information and to answer the following archaeological questions: origin, work-shops, and the various methods of manufacture. The fragment color is determined by the contents of oxidizing phases of the iron in ceramics. Up to now the origin and changes of the fragment color was examined empirically. Results were clumsy and the phenomenon of fragment color could be resolved into detailed information with the aid of physical-chemical methods only. A direct method for the examination of coloring is the determination of the absorption spectrum which would yield a more objective and differentiated description of the color as a remission spectrum versus the empirical one.