Here some nice articles : http://www.wetcanvas.com/ArtSchool/Color/ColorTheory/index.html (chapter 5)
There are some videos of old painting showing the effect on youtube if you want examples.
The code is “true” for ground objects, it should be inverted for the sky.
The code is not for physically correct results, but for our brain, blue color recedes and red color advances, same for saturation. Our screen is still 2d so I think it can help if you want more vibrant or 3d-ish perception, but you need to keep the effect subbtle, in my code it’s very exagerated.
You can use the selective saturation too for making important objects be more visible (they do this in L4D2, can’t find the article).
My next step will be to have focused camera object to be more saturated and background less saturated. I’ll post there or in fur shading when done.