Thanks for getting back to me. No I’m talking about the brownie green spot on the lower right side of the photo.Are you talking about the little white squiggly lines in the shell? That's nothing to worry about, and quite commonly seen in healthy young tortoises.
Thanks you so much. I was very worried there.No, that's not shell rot. To be honest, I don't know what it is. It appears to be inside the shell, under the top layer of keratin. Might just be normal coloration for this particular tortoise, might be a bruise. But I don't think it's anything to be concerned about. Just an FYI - shell rot first shows up on the bottom shell (plastron), not on the top shell (carapace).