What's the evidence that the colors were added later?

[Koen G]

But several people who have looked at the folio number with  a microscope (not just Rene and others at the workshoop, but, now I see, even the McCrone guys)  all agree that the paint is over the ink.

Do you have any exact quotes on this? It's important in this discussion, since so far the most important arguments are:

* The choice of colors looks weird (Does it though? And if it does, is that a problem?)
* Traces of paint material are found on top of a later folio number. On the same spot where we know water washed over the whole area...