Make leaf 1 day in advance. Tint white fondant 36 1/2 oz. gray and 1 oz. blue. Knead 1/4 teaspoon Gum-Tex into 1/2 oz. gray fondant.
Roll 1 1/8 in. ball of gray fondant. Use fondant roller with blue guide rings to roll out fondant 1/16 in. thick. Use straight edge of largest (1 1/4 in. x 2 1/4 in.) leaf cut-out to cut leaf. Use fondant roller to elongate leaf to 3 3/4 in. long. Use small veining tool from set to add vein and details on thin shaping foam.
Use royal blue icing color and water, royal blue icing color, white-white icing color and water, and white-white icing color and water to make paints in candy melting tray. Use brush and light blue paint to paint details on leaf. Use brush, dark blue paint and white paint to add more details until desired look is achieved. Reserve paints.
Use knife to cut notches, 1/4 in. to 3/8 in. deep, from leaf. Let dry, about 24 hours, in large concave section of wave former tray.