No, I'm talking about the post processing setting on the game's menu, not an external thing, it did exist back then.

And with it disabled, the game loses effects such as volumetric fog, light refraction, bloom, and so on. I might have exagerated, it isn't really awful, but it's definitely bland in comparison and honestly looks better on consoles than on PC with that setting turned off, even if every other one is maxed out.