There are two types of Steeple Keys. One of them is white in color with a clover-shaped end. The other one is purple with a circle end.
The white Steeple Keys are used to unlock the common doors in the Creepy Steeple including that one that leads to Doopliss. The purple Steeple Key is needed to unlock the basement of the Creepy Steeple that leads to a room with the Parrot and The letter "p".