f82v: those rainbows

[Koen G]

All I've got for now is that Isidore, in De Rerum Natura, describes rainbows as having four colors, in accordance with the four elements.

That's an interesting bit of information, might explain the somewhat limited palette we see in both manuscripts.

If you look really closely, you see that in the VM the band between green and blue is some faded yellowish color. Also in the other MS, the green seems to flow towards yellow. Though in both cases we must be cautious since the colors we see now may have shifted or faded.