Super Turbo Lighting Mod
This mod aims to please those who thought the game looked better as was shown back then, making plenty of graphical tweaks in order to make The Witcher 3 look like it did in those awesome early trailers. Amongst other things, the author has made changes to lighting in locations like Skellige and Velen, and also tweaked colouring and vegetation in other places like Novigrad. And the result is pretty splendid, giving the game a different look which may be more appealing to you on that second or third playthrough of this epic role-playing game.
Link to mod: nexusmods.com