Make cake. Prepare batter following recipe directions. Bake and cool according to pan package directions. Place on a foil wrapped cake circle.
Ice cake. Prepare buttercream icing following recipe directions. Tint portions royal blue, green, red, yellow and light sky blue. Use spatula and light blue icing to ice cake smooth.
Decorate cake. Use letter designs to press message on top of cake according to package directions. Use letter ?O? from press set to press rings on sides of cake. Use tip 3 and dark blue, green and red icing to pipe message on top of cake. Use tip 5 and tinted icing to pipe rings. Use tip 8 and light blue icing to pipe bead top and bottom borders.