No problem....can't fault you for caring about your now can we? I just thought it looked like his normal coloration, and those are the sort of marks
that are easy to miss on a normal day. I'm glad it's 'nothing' too.

As far as possible staining from substrate, I've seen that here too, on another thread...that snake appeared to have a stripe down his back, but actually, it
was just that he had rubbed his back on the very top, while his sides remained a bit stained, making the lighter area (which was actually normal) look like
a strange new stripe. I love a good mystery...