I've done some tweaks in this mod, like normalizing the skin color to be the same for all 10 costume colors, reduced the gap between the belt and the torned upper part of the clothing and removed the patch in the back (I know Roshi has it, but I didn't like in the mod).

Mod includes all 10 colors for Costume 4.
I haven't tried it in a different costume slot, so no idea if it will work.
If you want to try in a different slot, be aware you got to rename the files.

Drop the contents of the zip file inside your game folder at:
...\Steam\steamapps\common\Super Street Fighter IV - Arcade Edition\patch_ae2_tu1\battle\chara\GKN

If this folder doesn't exist, just create it.

The mod shouldn't overwrite any file, but make sure to have a backup of your original files before installing the mod.

I do believe this mod was originaly from dsFOREST:
https://www.deviantart.com/dsforest/art/SSF4AE-GOUKEN-kame-sennin-MOD-pack-292742142