Inherent characteristic of nature

Is COLOR a property of the mind or an inherent characteristic of nature?
Metaphysics is the study of what is real. Descartes said only two things are real: extension and duration. We say space and time, the four dimensions. In this Inquiry, we are looking into the nature of things in space and time, their characteristics; the characteristic that intrigues us here is color. So do some research into the modern science of color and give an argument on… where it is.