I’ve added a bloom filter, which every big title seems to use these days.
The bloom filter takes the brightest parts of the image, blurs them, and mixes the result back into the scene. This makes lights glow, softens bright edges, and generally makes things look more natural.
Since there’s very little light you can’t notice the bloom so much, although it’s very obvious on the bottom center bar indicator. The rest of the HUD does not have the bloom applied to it.
The blue sky effect resembles an aurora somewhat, and is animated. It’s obviously more interesting to see in motion than in this still picture.
Compare to this aurora below (courtesy wikipedia).