Processes for preparing high purity polycarbonates having high light transmission, low yellowness, and color stability are disclosed herein. High purity starting ingredients are used to form a polycarbonate powder. The polycarbonate powder can be subsequently melt extruded at an optimum shear rate to minimize yellowness and the need to add colorant to overcome the yellowness. The lower amount of colorant increases the light transmission of the resulting polycarbonate resin.