Raw Sienna was part of the old 3.0 version of Dark-Fine Tuned skins. It wont work with the new 3.1 version.
You would need to have the old Crimson skin and Raw Sienna together in the same folder for them to work, and even if you put them in the new Dark-Fine Tuned folder, they wont be updated to the new look.
Kandinsky Dark is not dependant on any other skin, so as long as you put it in the Skins folder (or any single sub-folder of the Skins folder) it should work.