No text, but a visual code

[Stefan Wirtz_2]

[..] I think it is likely that some later owner (probably not the Jesuits or Wilfrid) decided to have the book painted to increase its sale value [..]

Well, I don‘t think so. f 1r leaves space for the 2 big leading capitals (in some non-voynichese alphabet) which are intended there by the author and coloured red.
One of the rare occasions where the VMS follows the standards of medieval manuscripts, red-coloured capitals were a rather common way of starting chapters, sentences or books.
If one thing is clearly set for colouring, others can be that also.

There is no reason and, more important, no proof of the VMS becoming some kind of colouring book much much later.
I would asssume several scribbles, in words, sentences and „graphical“ content, being added a long time later, but not the colours.