Color is a psychological construct of our visual experience that represents an interaction between the physical properties of objects in the environment, the illuminant, and our nervous system. This chapter describes how the psychophysically measured subjective experiences that arise from signals originating in the retina lead to chromatic and achromatic visual perception. We explore how the processing of cone and melanopsin signals under photopic illumination; the interaction between rods, cones, and melanopsin under mesopic illumination; and rod signaling under scotopic illumination give rise to human color vision by examining links to retinal physiology and the effect that individual variability has on visual perception.