A few nights ago I got my shoes/feet wet. I wore them for several hours. When I took them off, my feet were so much lighter. How did damp shoes cause this effect?
Same thing when you take a band-aid off, and the skin underneath is all gross and pale and wrinkly? Whatever causes that?
WAG - The outer layers of your skin are usually somewhat dry and transparent, getting them wet makes them less transparent.
For band aids I’ve really only experienced it as a tiny tan line.