I've been recently noticing this dark spot forming on my foreskin. It's not really a focused spot but more of a dark smudge "as if I had black ink on my hands and I slightly touched my penis" kind of spot. It's not bumpy or has any texture to it, but looks more like my skin just got darker at that spot. When I'm flaccid, it's darker since my foreskin isn't stretched, but when it is, it looks like the dark skin is broken up into smaller portions, not really connected to form a dark patch, kind of sense. Can't really explain it any better than that.
Been reading around and some sites say it's pigmentation and some might suggest it's melanoma. I've looked at some of the pictures of melanoma and most looked different than what I have with their raised, bumpy texture, and shiny look to it so, I don't think it's that.