What does color shift top and bottom do?

[Hamburger_Hoovy]

I’ve been messing around with lighting recently and I saw the color shift bottom and top properties in Lighting’s properties. When I change the color of them, I don’t really see any results. So, what is color shift bottom and top?

[TheCarbyneUniverse (Carbyne)]

The ColorShiftTop property controls what the side of a part that is facing the sun looks like while the ColorShiftBottom is the opposite, the side that is facing away from the sun.

Edit: Setting ColorShiftTop to 255, 0, 0:

ColorShiftBottom: