What color is the underside of skin?

Today, I read a friend's away message that simply asked, "What color is the underside of skin?"
It was probably the creepiest question I'd hear all day and therefore I needed an explanation.
It turns out she wasn't consdiering a career as a serial killer, she simply discovered a poem that is able to ask this question in the most non-serial killer way possible. If you feel like reading a lovely poem today, visit the Academy of American Poets to read "A Green Crab's Shell" by Mark Doty. And thanks for introducing it to me, Emily.