Make bow. Using Red-Red icing color, tint ½ oz. fondant red. Using fondant roller with purple guide rings, roll out fondant. Using round cut-out “F”, cut out one circle. Using knife, cut two triangles with rounded corners to form bow loops, measuring 1½ in. wide at widest point and 1¾ in. long.
Prepare royal icing following recipe instructions. Using Royal Blue icing color, tint 1/8 cup icing blue. Using Kelly Green icing color, tint 1/8 cup icing green. Reserve remaining icing white.
Prepare decorating bag with tip 2 and blue icing. Prepare additional bag with tip 1 and green icing. Alternating between blue and green icing, pipe loose basketweave pattern on bow. Let dry, about 5 minutes. Attach bow to base of cake, using remaining chocolate buttercream to adhere bow, if needed.