Radiative transfer theory concepts for color-matching calculations of solid color coatings are reviewed. Two flux approximations to the exact radiative transfer theory for isotropic scatters are developed. The Kubelka-Munk theory is discussed in the framework of two flux theories. A comparison is made between reflectances calculated from the Kubelka-Munk, two flux approximate radiative transfer, and the exact radiative transfer theory for 45/0 and diffuse/near-normal measuring geometries. A color-matching method is presented for radiative transfer color-matching calculations. This method, which can be implemented on a personal computer, is shown to give good color marches for the exact radiative transfer theory. The proposed color-matching algorithm, which can be applied to all three models, gives results equivalent to established Kubelka-Munk calculations. A comparison of the Kubelka-Munk, two flux approximate radiative transfer, and exact radiative transfer color calculations shows them to give equivalent results for diffuse/near-normal reflectance data.