This photo I also took with my cell phone and the colors, especially the shadows in the trees are much bluer and brighter than in reality. It's very misleading. Sorry.
I began painting the trees on the right that are catching the light. I used slightly different colors suggesting the brilliant autumn foliage: variations of burnt sienna, yellow ochre, cadmium red light, cadmium orange and my premixed greens. I add the blue-violet mixture to the shadows. (Fomulas for the greens and blue-violets are in my book shown at right, Secrets to Composition, as well as my painting procedures.)