Confession: I keep a messy palette. I use two John Pike Palettes, deep well, and I usually have colors flowing everywhere. Once a week (or month), I like to clean my palatte, and it is very satisfying--similar to dusting after a long break. Sometimes, the mess on my palette produces interesting grays, and I like to try and incorporate them into new paintings, and here are two paintings that lean towards muted grays done from what's happening in the mixing area of my palette..
The first painting (left) is called Move Into The Light, and shifts from the grays to tonal reds, blues, and yellows. It is 4 inches by 11. The second painting (right), Horizon Line, and is 11 x 6 inches. It's a balance between two grays, and has a minimalist wintry feel.
In both cases, I was just playing with some colors that mixed on my palette, but I was especially pleased with how the paintings came out.