This mod changes most tiles of the game by adjusting the hue and/or saturation of them. The changes are mostly subtle, without making anything look too much different from the original.
While there isn't anything wrong with the original graphics, it can get a little repetive to look at the exact same graphics all the time, so I made this mod to change the look a little bit. This was fast to make, since I didnt actually make any new textures.
Screenshots with comparison: 
How to install (short version):
1. Replace alltex.wad/ALLTILES/alltiles.png
How to install (long version):
1. Download and extract the spelunktool
modding tool to a new folder
2. Make a backup of alltex.wad
, which are found inside the data/textures
directory of spelunky HD.
3. Copy alltex.wad
to the place spelunktool was extracted to.
4. Drag and drop alltex.wad
on top of extract.bat
; A new folder named alltex
will be created.
5. Replace the alltiles.png
found in the alltex/ALLTILES/
folder with the alltiles.png
provided by this mod.
6. Drag and drop the alltex
folder on top of repack.bat
; The alltex.wad and alltex.wad.wix files in the spelunktool directory will be replaced with new ones.
7. Copy the alltex.wad
files from the spelunktool directory to your spelunky data/textures
directory, replacing the original alltex.wad
files (Make sure you have backed them up first!)
8. Launch spelunky and hope that it works!