Installation:
Only if you use RotWW version: Make sure you have Rise of the White Wolf Enhanced Edition installed! Modlink: http://www.nexusmods.com/witcher/mods/669/?
Open the folder of your preference (either "Dark Blue" or "True Crownflower") and just extract the data folder from it to your main The Witcher directory where the game.exe is located and choose "Yes" if asked for overwrite things. (normally: C:\Program Files (x86)\Steam\steamapps\common\The Witcher Enhanced Edition)

Credits:
All Credits goes to rustine! I just edited the textures of his mod.

Enjoy!