And this is why I did my best to photograph and document the film of dirt that has built-up and baked-on.
Hi Jim,
Good eyes. And "yes" there is a very dramatic color difference in that section.
For those that might not be able to see what Jim's talking about, perhaps you're looking at the picture on an old monitor or your cell phone, Here's the same picture above only I've drawn a circle around the section that appears to be darker than surrounding paint including the bare-naked paint below it.
I always like the easy-wipe-off characteristic if you let if fully dry.