Yeah, I think a brain is critical for translating colour theory and selecting the correct values. So I understand exactly where Michaelangelo was coming from. Obviously my hands will mix the colours, but I only use the primaries, burnt umber and white. So a lot of theory is involved.
And for disclosure, my palette after that last painting I posted was a MESS. It's one of those times when owning a few extra tubes is helpful.
To be honest I feel like 85 to 90% of it is understanding colour theory. If you can take decent photographs and understand what you're seeing, then that's half the battle won already.
And I think maintaining a bit of abstraction in your brushwork helps as well. I'm not necessarily at a high level yet, but I'm starting to figure out what works. Everyone likes brushy texture in a painting.
Not the best images though, I need to upgrade my camera.