To incentivize solar panel adaptation, a multitude of solutions are actively being researched. Among these solutions are colored solar cells, using coatings or filters to open the door for more architectural expression. In order to help architects explore these possibilities, it is necessary to enable flexible, fast, and realistic visualization. This work explores the modeling of color-coated photovoltaic cells using a physically based bidirectional reflectance distribution function (BRDF), with a focus on the pyramidically textured structures embedded inside many of these cells. The BRDF is analytically derived, modeling light interactions as recursively specular multiple-scattering. The model is parametric, characterizing the surface using its pyramid density and pyramid slant angle, making it generally applicable to homogeneous pyramidic surfaces with uniform pyramid heights. Evaluation indicates the model closely approximates the behavior of generated references at steep viewing angles. Clear avenues of improvement, including corrections at shallow angles, are discussed within the context of future work.