Weird effect on Foamposites

So I was given a pair of wolf grey foamposites by an optimistic friend who wanted them repaired. I saw them as not being able to be saved so i threw them in the back of my truck in my drive way. Today, i went out to put them on so i can cut the grass and to my surprise, the shoes changed color.

Now this could be like the dress and my eyes are confusing me, but I wanted to get some feedback. Has this happened to ayone? Has anyone seen or heard of this? Thanks

P.S. I don't know what caused this. It could've been rain or sunlight.

This is the original shoe

Sunlight I suppose. Flip it over and put in the sun for a while and see what happens

i did and nothing happened