It would be really nice to be able to have custom LUTs to control the feel and look of the game. The unreal engine is a good example of what I am suggesting, you have a small colour pallette which you edit and this is then used to apply the post process. (https://docs.unrealengine.com/…tProcessEffects/UsingLUTs)
An example of some different looks I created in photoshop to get an idea of the effects:
Personally I think my edit has a much more natural tone to it and the lighting is less washed out. I would love to be able to use a change like this in game and switch between them.
Custom maps could use them to set the mood, could make for some cool builds.