Bloom too Bright in Borderless Windowed

The game is too bright (specifically, the bloom is blinding if you are looking from under shadows and out into any position above you that is in direct sunlight and has anything white in the area).
With no option to turn off the bloom, and my current setup making fullscreen unstable, I need a way to turn down the game's brightness and none is offered. I know I can turn down my monitor's brightness but that doesn't actually address the problem here as it will create new visibility issues, and is not a user friendly fix (having to switch brightness for one game is gonna discourage me from playing the game period).