I mixed up 3 shades of blue gray for my underpainting, so I could plan my lights and shadows. I decided to use cool grays for this because when I go over it with layers of warm glazes, they will visually lift off the underpainting. It’s fun to work on a violet tint. If you want to experience”lift” you should try it. The violet is kind of transparent and seems to rub off on your hands, even if it’s dry. You can tell when you paint on top of it that it’s coming right through the underpainting colors. That’s ok, because as I’m building up layers on top of the violet, I can totally kill the violet if I want to, or I can let it show through in places. I like when it shows through. I don’t know if others can see it in the end, or if I’m the only one who sees it because I put it there. But the violet continues to influence the glazes on top. If I let it show through in the shadows, it will be muted violet, not VIOLET!! haha. You know what I mean.
It’s a fun color theory experiment, and it works.