If its around the rug and not underneath where the rugs was located... it is likely its from the oils on shoes that come from a black top driveway. Blacktop will continue to give off an oily residue ..enough to discolor high traffic areas of vinyl flooring.
I have the same issue around the perimeter of my kitchen cabinets but not that 3 inches under the cabinets. I was baffled at why this would happen. Logic would indicate the area under the cabinets would discolor as it might not get cleaned as well. When I really examined where the area was that was most affected it was in front of the refrigerator ( of course) in front of the sink... but the area were I stood the least had no yellowing.
A flooring person clued me in when I was researching what kind of floor to replace it . He asked me "do you have a black top driveway and leave your shoes on when you come in the house?" I said yes and he told me the last thing to consider is vinyl or I will have the same problem.
Just to further investgate .. asked my neighbor with a concrete drive way if he had yellowing of his floors... NOPE , no issue .
Last edited by Lori S; 03-19-2014 at 01:00 PM.