You have to figure: Color Blindness is a recessive trait (at least in humans, I don't know about other species). In order for it to survive, and even increase i

You have to figure: Color Blindness is a recessive trait (at least in humans, I don't know about other species). In order for it to survive, and even increase in expression over the course of human evolution, it has to carry with it some benefits (admittedly, it is also carried on the X chromosome, which has found to be highly linked to IQ). You also find color blindness in several species of animals, particularly those that are predators. To be honest, it isn't an optimization. Its a trade off, that has benefits. An example would be being able to see infra-red light. You would be able to see more colors, which comes with all sorts of advantages (distance the color carries, how well it reflects, what it reflects off of, etc), but the trade off would be you would be even worse off when looking at a pattern. For whatever reason, the human brain (at least, this may be true for other species) considers color to encode quite a bit of information, and it is quite high up on the list of things to process.