What you see in real life is the total from of all light information.

Be it sunlight, a lamp, a reflection, the color of the surface.
All interact to give the eye the total light and color information on each spot.

In my house, I have rather small windows.
As the sun turns around, the light, and the reflections change.
From the east it is open field, then comes a forest, then some green, to a brown wall in the evening?
As the sunlight passes over each, and gives different reflections, the "light" inside the house changes too.
The floor is a rather dull light grey-brown stone, but it still reflects the incoming light.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!