My brother inlaw studied eyes in college and confirmed my suspicions.

White is an odd thing that we are blind to, our rods pick up the primary colors which turn into white looking light or white paper ect..

Then I asked him about a dim corner in his house.  Places we see all the time where the solidity of the physical material seems questionable.  Wtf is that?  He saw it as well, but failed to explain it when he tried.  So please help if you can?