Achromatism is a big degrade on performance, especially on lower-end hardware. I have the effect off in the video settings, but sometimes in-game I will find that it is somehow activated but I go into the video settings and it is off, I turn it off and back on and the effect is gone. Later, I will see the effect again and have to do the same thing again. here are some examples of achromatism for those of you who don't know what it is