Slightly Grim SweetFX is a mod that makes the game slightly more grim. It removes the yellow/orange tint from the game and makes the colors a bit darker.

It will make Geralt more white and less colorful. If you have a very pale geralt mod it might be too much.

It's a very slight modification and it doesn't have any special effects that take away from the game's performance. It's meant to be used with the vanilla lighting mod and it still looks great in my opinion.

If you want to change something simply open the file and change what you want.