2 Pastry bags; Ateco #104 rose tip; Ateco #2 small round tip; Ateco #70 leaf tip
Frost the cupcakes with the buttercream.
To pipe the flower: Place the grape-tinted frosting in a pastry bag with a #104 rose tip. Point the bag down at a 45 degree angle, with the skinny end of the rose tip aimed towards the center of the flower. Squeeze and release while making 5 tear shapes in a circle to form a flower. Repeat piping on top with 4 more tear shapes in a tight circle.
Place the egg yolk-tinted frosting in a pastry bag with a #2 small round tip. Hold the bag straight up, and pipe a small dot into the center of the flower.
To pipe the leaf: Place the avocado-tinted frosting in a pastry bag with a #70 leaf tip. Point the bag down at a 45 degree angle with the tip lightly touching the surface of the cupcake. Squeeze hard to build up the base and simultaneously lift the tip slightly. Relax the pressure as you pull the tip toward you, drawing the leaf to a point. Stop squeezing and lift the tip away. Pipe a second leaf on the other side of the flower.