Don't remember and don't have it anymore... I remember one of my first tilesets was one that was supposed to show the insides of Spaz' body. It had teeth, one-colored red ground tiles and a more darkly colored red background tile. And tile baddies. \o/
...when I first did this tileset, I think I kept trying to find out what color makes stuff transparent ( without success... )... and I forgot to use the grid at one point and just kind of blurted stuff where it seemed to fit. *cough*