Bob!
I have started the Matisse impression and include some images below! It's possible that I have figured out 80 percent of his paint mixes. Starts with old reliables then increases the colours using ones already used mixed in! That's how he tones down the orange. The yellow and blue can be used to create the green with different hues. He then used some old equivalent to a Payne's grey, or mix of something like titanium white and Mars black. Modern colours are so much less effort.
Image below is background to test colours. Loads of fun and must stop myself from getting carried away!
Arthur
