The Neural Control of Vision
J. The Processing of Color

In the cortex color processing is further elaborated, but at present there is still a lot of debate about what goes on. It used to be thought that there is a special color area in the brain, area V4. It appears, however, that many areas co-process color. In fact, when area V4 is removed in monkeys, what is striking is how little basic color vision is affected. Figure 45 shows color discrimination like the one that had been shown in Figure 30 with data added from a V4 lesion.