Returning to the blemmyes, we find that their skin, so human in tone, is not a painted color, but simply the real skin of which the page is made.I hadn't yet seen any of these three images in person, and was working with the black-and-white facsimiles in the EETS series (for Vitellius and Tiberius), and then with a few color reproductions I'd been able to track down.
I have since seen all three manuscripts, and it turns out that I was not only flatly wrong, but that the actual situation is much weirder: The image of the blemmye in the Tiberius manuscript (online at the BL in, it seems, odd color, here, but the image in the current post is better) is indeed painted, but it is painted a shade of beige, of what Crayola, prior to the raising of consciousness of the civil rights movement, used to call "flesh color." I have asked Routledge to let me fix this, since they are still printing the book, but no dice. The error is there, in perpetuity, when the bizarre truth is much more interesting.
There are losses to the image, and they are barely perceptible. Why bother to paint the figure a shade that is almost totally indistinguishable from the color of the vellum? Does this mean something? Surely. Another book,* another time.
*(Note of further fumble: I intended to get this correction, at a minimum, into a footnote in a new book on the Wonders, but that is now done, and I seem to have lost that note, somewhere along the way...)