Colorization - what was it's purpose?

[Koen G]

"Who put these weird and sloppy colors in my weird and sloppy manuscript?"

Just to say, I agree that the colors are problematic, but this is completely in character for the MS. I'd see this as evidence for their authenticity. Lest we forget that the vast majority of Voynich plants are impossible to identify and that we've got nymphs with arms attached to their bellies and lobsters with legs on their tails.