Can you compare to a white/white(or light as possible)?
Gray is some percent black.
Well, it’s winter now in Iowa.
Inside of cars get hotter in summer than one might think. We saw 165 degrees on a vinyl dash. Leather didn’t get as hot but it actually felt hotter to the skin than fabric.
People have done this before:
http://phys.org/news/2011-10-silver-white-cars-cooler.html