[OldJimi]

What makes me think getting walked on is a factor is that the yellow is in the center but not so much in the edges or under the slide material. I know longer think it's from asphalt oils or debris being tracked in, I think it's the oils used to keep the linoleum pliable coming to the surface as it is subjected to pressure. I have a piece of the linoleum that was cut out, maybe i'll lay it out and start pounding a corner with a rubber mallet.
When the issue was discussed with Keystone, their response was that the floor wasn't really new, since they shipped it to Oklahoma 9 months earlier. Camping World may have moved it around a bit to RV shows before it landed down in South Florida. Who knows.