A Gaussian-distributed excitation light beam of an excitation spectrum emitted from an excitation light source enters a light pipe and is there converted to a top-hat spatially distributed excitation beam. The top-hat distributed excitation beam is focused on a phosphor-coated or reflective portion of a surface of an optical wavelength conversion element. Fluoresced and reflected beams travel outward from the wavelength conversion element and re-enter the light pipe to be homogenized during transit through the light pipe. A homogenized fluoresced or reflected beam is relayed to an output as one of a sequence of colors of homogenized light. The functions of Gaussian to top-hat conversion of the excitation beams directed toward the optical conversion element and homogenization of beams directed outward from the optical conversion element are both efficiently performed using a single, shared light pipe.