Protanomaly is the second most common type of colour weakness (a mild type of so called ColorBlindness). Like most people, they have three channels but their red channel is shifted towards green. As with DeuteraNomaly, protanomaly causes red-green color on background combinations to jump out less and reduces distinctions between small hue differences in the red-yellow-green region, but instead of deep greens appearing black, there is instead a darkening of the red end of the spectrum. This can cause browns and dark reds to be mistaken for black.