Traditionally the mixing of colored lights as that produced in a visual colorimeter and the mixing of colorants used in paint mixtures have been considered additive and subtractive coloration systems, respectively. Although mixing laws have been developed for each case (the so-called Grassmann and Kubelka-Munk laws), many systems can not be accurately described, or use both additive and subtractive mixing.Usually mineral components have been previously considered as colorants, and consequently only subtractive laws have been applied to soil coloration systems. In this work we have tested the use of the Grassmann (additive mixtures) and Kubelka-Munk (subtractive mixtures) theories, in order to analyze the coloration in soil mineral blending systems.We used 12 soil mineral mixtures making four separates of each with different mineralogical composition. The color of the mixtures and separates was independently measured using a PR-704 spectroradiometer and a D65 luminous source.We computed the relative difference between the measured values in the mixtures and those estimated from the mineral separates using mixing laws, for CIELAB coordinates L*,C_ab*,h_ab, and K/S parameter. On the average, these relative differences were 0.07 in L*, 0.23 in C_ab*, and 0.03 degrees in h_ab using additive law, and 0.19 in K/S using subtractive law. These results suggest that the soil coloration systems studied here could also be appropriately described as additive mixing, in particular for soil samples having low Fe-oxides content.