1.  Place cereal in a large mixing bowl.
2.  Melt chocolate and butter in a microwave safe bowl for 1 minute.  Stir to smooth.  If needed, microwave for another 15 seconds to completely melt the chocolate.  Add a dab of purple gel coloring and mix.  You want a deep, rich purple color.
3.  Pour the chocolate over the cereal and gently mix them together, careful not to crush the cereal.  Add about half of your sprinkles and mix again.  Add the powdered sugar and mix until the cereal is evenly coated.  Finish off with a few more sprinkles on top.