Humans with red-green color blindness, see a different spectrum blame it to the dichromacy (two types of cone cells) rather than trichromacy (three types of cone cells) in normal Humans. Have you ever imagined what would have happened if we had not been blessed with trichromatic vision and how we developed this, thank our fruit-hunting ancestors, claimed by a report shown at the annual meeting of AAAS, which publishes Science.
Few of the primate species (our early ancestors) have three different types of light-sensitive cone cell in eyes (trichromacy) rather than two which makes primate exceptional and allows humans to explore what we think of as the standard spectrum of color. As per the hypothesis, the satandard explanation for trichromacy in primates, is that it allowed them to see colourful ripe fruit more easily against a mostly green background of the forest. The rhesus macaque (a particular Old World monkey), has a genetic discrepancy to offer a convenient natural test of this hypothesis. A common mutation makes some females have three types of cone cells whereas others having two only. Based on a study report including >20000 individual observations of 80 different macaques feeding from 30 species of trees on Cayo Santiago, Puerto Rico, researchers can say with some confidence that wild trichromatic female monkeys do certainly seem to trace and eat fruit quicker than dichromatic females monkeys, leading strong support to the idea that this differentiating advantage of trichromacy over dichromacy helped drive the evolution of trichromacy in Humans and other relatives.