As an "expert viewer" of Baumgartner Restoration, this site usefulness is questionable. If you look at those color palettes, most of them brownish that is because of dirty & old oxidised varnish. These are not the intended look of these paintings. So these color palettes has nothing to do with those 3000 masters. https://youtube.com/@baumgartnerrestoration
For some additional context; many old pigments were not stable at all.
https://www.vangoghstudio.com/what-were-the-original-colors-...