I made the leaves all in white, and used petal dusts to color them. I decided to use the dusts instead of an airbrush because the topper had a more rustic feel to it, so I wanted the leaves to have the same kind of dusty tone. Since coloring with the airbrush can give you a more shiny kind of look, I didn't go with that this time.
One common mistake that people make when they're coloring leaves is to make them all one flat color. Just like the pumpkin cake, if you use a range of colors it will give the leaves more depth. For these, I used a combination of oranges, yellows, some deeper reds, browns and even some darker green.
The cake itself was iced using horizontal ridges on the sides of the tiers, which added to the rustic feel. I dug out a little Wilton edging tool to do that, then touched it up with the spatula. You could do the entire thing with a spatula, it would just take a little longer.