This is about his fading pigments. There are letters of his where he acknowledges that he uses bad quality paints that are likely to fade, which is why he uses stronger colors than he knows he should.

The linked article (which has very few pictures, this link to work by the original researcher has much more: https://asada0.tumblr.com/post/11517603099/the-day-i-saw-van... ) is about something else, namely a form of color blindness that distorts your vision in ways that are a lot less obvious than the way more common red/green or even blue/yellow color blindness.

I’m not an expert, of course, but to my layman’s eyes the “corrected” images look much, much better than the u corrected ones (you’ll need to see them indoors, however, on a reasonably good screen, to truly appreciate the difference). Uncorrected van Gogh’s work always strikes me as flat, lifeless and therefore amateurish. The corrected ones have much more depth and therefore, while garish, strike me as much more competent.