I don't think that most of the paintings look better or more interesting in the protanomal simulation, some of them actually have lost their magic and look dull. I find this most visible in the self-portrait, of which the author writes:
the man whom one cannot approach easily.
The tinge of green in the original portrait makes this man much harder to approach, because it adds the psychotic, unusual aura to the picture. This man has left the world of commonly shared human experience.
The author remarks that in the picture The Road Menders the trees have a strange color and after conversion look more solid, giving some depth to the road. So the picture looks more like what we would expect, in other words: we see the usual.
But this is contrary to the kind of psychotic perception of the world, which I associate with van Gogh's paintings, at least with those paintings that we would call typical van Gogh (there are paintings from the earlier dutch period, which have a different character): Reality is distorted, colors deviate from the ordinary, everything is flowing together and swirling, the wheat, the sky, the world. Proportions are deranged, look at the painting of his bedroom for example:
http://de.wikipedia.org/w/index.php?title=Datei:Vincent_Will...
Theo van Gogh, his brother, wrote 1889 in a letter to his future wife a characterization of Vincent van Gogh: "As you know, he has broken since a long time with everything what we call convention. The style of his clothes and his behaviour show that this is a special human, and since many years people who see him will say: This is a madman."