Advance Sprite Palettes

In FF6Tools, when you click on Character Graphics, and go to where you can use that drop down menu on the right to select what color palette to display as, there are 4 weird color palettes there.

They may be used, much like the rest of the palettes. I don't think someone ever discovered some palettes were unused, and as far as playable characters goes I think you can only assign palettes 0-6 but I could be wrong.