Method for employing colorants as indicators in polymer blending

In the formation of polymeric materials using a two or more component reactant mixture (i.e. A/B system) and a pigment or colorant, the color of the final product can be used as an indicator to reveal if the correct ratio of A/B is being applied in forming a polymer product. Exact measurement of color may be proportional to the amount of color used in the original reactants A and B. Thus, this enables relatively fast adjustment of the reactant ratio A/B based upon measured color results of the final polymeric product. Too much of a first color indicates a corresponding excess of the first reactant, while too much of the second color indicates an excess of the second reactant. The system has application to polyurethane materials.