I don't get too excited about selective coloring usually, but find it very effective here. I'm enjoying the spectrum of grays and of course, the huge shadows.
Good Selective Desat. I would like to see it with the green lawn to compare because I think that the red leaves would pop off of that as well. BUt here, the greytone background gives it the emotion/impact of a B&W image with the pop of color to give it that fall foliage flare!!