In light of that, here is a big Grand Canyon painting from a couple weeks ago. It's 3x3 feet
"Glowing Depths" Oil on canvas, 36"x36"
I limited my palette a little bit more on this one. This time I was using:
Cadmium yellow light, yellow ochre, cadmium orange, Bright Red (Winsor and Newton), ultramarine blue, and viridian hue (Holbein). I used very little cadmium yellow in this piece. Most of it was in the foreground trees and that's it. Yellow ochre was my primary yellow here.
A note on Reds:
Bright Red from W&N is a great primary red. I use it when I want to limit myself to just one. It's bright and light in value, but it can still mix decent violets, which is important to me in a red. The other great thing about it is it's a series 1, which means it's cheap!
Bright Red isn't all that great though. It's semi-transparent. When I allow myself two reds, I tend to go with cadmium red light and alizarin crimson instead. Crimson gets me those nice purples and makes great muted blues when mixed with viridian. Cadmium red light is a great starting point for earth tones. I also love the way it can grey down a purple. I really find myself relying on the opacity of cadmium reds when painting as well... something I didn't really realize until I got rid of the cadmium red. It's funny how we end up relying so much on specific materials.
Sometimes I like making myself to use different materials, as a way of forcing me out of my comfort zone. It makes me think differently, and often times I'll learn something new.