No doubt, post is a big part of the process. Factor in other things like linear workflow (gamma correction) if working with MR, lighting, monitor profiles, etc....there are a lot of factors to deal with. My suggestion would be to render things out to give you most control over individual elements (render passes for various elements, then work in post to work it to the original source colors).
"Terminat Bora Diem, Terminal Auctor opus."