This is a texture pack that comes from the Arkanes texture pack, and excellent texture pack that I would highy recommend. Here is their link

www.planetminecraft.com/texture_pack/64x64-124---arkanes-ultimate-texture-pack---created-by-scyzthe/

This texture pack is not ment for use at all times, It is just a pack that makes EVERYTHING look dark, dreary, but sometimes beautiful. It completely changes your world. Try it out!