Melt vanilla candy wafers until cream. Pour into the shell mold and place in the refrigerator until solid. (about 8 mins)- pop out shells and set aside. Divide the frosting into two microwave safe bowls and melt for 30 seconds or until creamy. Drop 3 drops of each coloring into the melted frosting, and mix each. Dip each donut into the color of your choice and place them on a wire cooling rack to drip. Sprinkle with sprinkles, and add a candy shell to each. Allow to cure for 15 minutes or longer.