https://wccftech.com/the-witcher-3-enhanced-toussaint-mod/

The Witcher 3 received a brand new area with the Blood and Wine DLC, the Duchy of Toussaint. The area looks very different from the other locations of the game, mostly due to the lighting, which makes everything vibrant, maybe even too much. If you don’t like the exaggerated look of Toussaint, you will be happy to know that a new mod changing the lighting of the area has been released today.

The Witcher 3 Toussaint Enhanced Mod changes the lighting in the Toussaint area, making it look more natural and more in line with the lighting of the other areas of the game.