The beauty of turning Autumn Leaves, Sunsets, Colors and Emotions.
This is a great study (see below) discussing how the human brain processes visual natural scenes, maybe even to a greater extent why sunsets, waterfalls and mountain scenes make us feel good.
When we view a natural scene such as a beautiful mountain view, much of our visual system spatially orients the surrounding objects, helping understand the scene within the current time frame. High level processing within the visual system requires communication among the specialized regions of the brain. In another part the visual system we process how to place that scene in context with past similar experiences.
“With respect to natural scene perception, one can imagine at least two separable functions: processing the specific visual features present in the current glance of a scene, and connecting that to the stable, high-level knowledge of where the place exists in the world, what has happened here in the past, and what possible actions we could take here in the future.” "Two Distinct Scene-Processing Networks Connecting Vision and Memory”
So the emotions that we feel upon taking in the sunset, or beautiful mountain view are part of us placing in context the beauty surrounding us, then understanding its proper reference frame.
This internal brain communication is possibly why as humans we stop for a moment enjoy that sunset, take a deep breath, contemplating past, present, and future.
Our brain connects the many possible emotions, ranging from our past experiences to the hopeful potential of the future. Cross referencing the current scene with a happy childhood camping memory in the fall, or future plans for returning to watch the sunset again soon.