Actually, the post-processing tool he used is called a paintbrush. It’s used to apply colors on top of the image that aren’t naturally present. You can tell by looking at the lazy paintbrush strokes he used, like on the red tree in the water and on the bigger green patch at the bottom center of the frame - funny how only the top half of that green tree has a stroke of orange color and the bottom half doesn’t yet the whole tree is surrounded by orange leaves. I guess you’ll agree this is not the artifact of color bleeding or blown out colors.