Word of the day : Chromatic black.. my new best friend. Didnt know it existed.. not really. I see now where BR is actually using it for his darks but now I understand of the method behind the madness. Easy to make.. tho you can buy it. I'm starting to do this more.. make up my own shades of paint and then store them. I have not gone as far as loading my own paint tubes but I'm starting to see the logic of that.
This is a great link as to what is chromatic black and why it's so darn useful
Other new colors to me.. "Anchor Green" and "Marine violet" .. both are from Debra Huse and she does offer up the recipes. She has an interesting training video.. kind of impressistic style for marinescapes.
https://www.liveabout.com/art-tutor-and-the-chromatic-black-2578044