Optical properties (i.e., reflectance, transmittance, etc.) of light scattering materials can be described using two approaches. In the first approach, the interaction of light with the matter’s particles is modeled (microscopic approach) while in the second, the light fluxes into and out of bulked considered matter is modeled (macroscopic approach). Kubelka-Munk (KM) is the most common theory of macroscopic modeling, for calculating the change of light fluxes (two-flux theory) as a function of scattering, absorption, and distance. Modified KM Models, for calculating the optical properties of rough surfaces, revised KM theories as well as, inversion methods from KM analysis are presented. A KM and Mie microscopic model is used for emmitance calculations of coating layers. Three flux models track two diffuse fluxes and one collimated flux, while four flux models track two diffuse and two collimated fluxes. Maheu- Letoulouzan-Gouesbet (M-L-G), multilayered, and other generalized four-flux models are shown. A number of applications of the discussed models in pigments (such us polymer coatings), light scattering from TiO2 and red particles are also presented.