Dogmeat's Special Sauce is my personal preset that I done made and you can have it too. It makes everything seem a bit colder and more crisp, and makes indoor areas darker and more foreboding. This preset is designed with little to no performance impact, although if you want a cheeky breeki more looky goody you can set "#define USE_AMBIENT_LIGHT" to 1 in GemFX.cfg.
I know it looks very bluey-greeny in the screenies but use it for a little while and it really works.
Click download preset. Open. Go to the link. Download. Unzip. Main game directory. Enjoy. Or Don't. Just don't hit my dog.