In advance: Make fondant flowers. For every 3 cupcakes in colors shown, tint a 1 in. ball of fondant blue, 2 in. balls yellow, rose and violet. Roll out colors 1/8 in. thick. Using Flower Making Set cutters, cut 6 apple blossoms in violet and 12 forget-me-nots in rose. Place flowers on thick foam and cup centers using round stick from set. Let dry overnight on cornstarch-dusted board.
Ice cupcakes smooth. Roll out remaining fondant colors 1/8 in. thick. Cut blossom brims using 2nd smallest metal cutter; position on cupcake.Roll a matching color fondant ball, flatten to 1 1/2 in. wide x 3/4 in. high; attach in center of brim with damp brush.Cut blue hat bands, 1/4 x 51/2 in.; attach with damp brush. Outline brims with tip 1; add tip 1 dots at petal points. Attach flowers with dots of icing. Pipe tip 2 dot centers in buttercream. Pipe tip 349 leaves.