This study aimed to investigate how variation in iris color, along with ethnic origin, affects color vision. For color vision deficiency screening, the Ishihara, D-15, and D-15d tests were employed. Chromatic discrimination was assessed in normal trichromats using the Cambridge Colour Test (CCT). Three groups were tested: light-eyed White (N = 30), hazel-eyed White (N = 30), and brown-eyed Black (N = 29). Black observers revealed significantly higher CCT measures—protan and tritan thresholds (Trivector) and Ellipse measures (major axis, axis ratio, and angle); no significant differences were found between the two White observer groups. We attribute Black observers’ subtle tritan-type impairment to prereceptoral factors, in particular, the higher optical density of the macular pigment, which filters out short-wavelength light, affecting S-cone-mediated chromatic discrimination, and, also, is likely to reduce retinal illuminance. The elevated protan thresholds are discussed in relation to the receptoral level; considered are possible causes of genetically determined L-cone characteristics in observers of African descent.