etabeta, thank you very much! A great article indeed. And we see how vibrant are these colors still, after hundreds of years.
If you don’t mind me asking, are you a painter?
I wish I were a painter! Unfortunately I have zero talent but a great love for art, curiosity and I read a lot. I used to take a painting, enlarge it and lift a detail. By studying the details, I think we understand more of the artist, the times, the culture, their vision. I get enthusiastic when I discover little treasures in a painting.