Prepare 2 baking sheets with silicone mats, teflon, or templates and parchment paper. Fit a piping bag with a round piping tip. Set aside. Preheat oven to 290°F.
Pulse the powdered sugar, almond flour, and pumpkin pie spice in a food processor and sift into a bowl. Discard any large chunks. Whisk the dry ingredients and set aside.
Combine egg whites and powdered color.
In a clean stand mixer bowl, combine the sugar and the egg whites. Whisk to combine and place bowl over a double boiler. Heat, whisking regularly, until the sugar dissolves, about 90 seconds. Remove the bowl from the double boiler and carefully dry off the bottom.
Place the bowl in the stand mixer and whisk on a medium speed (KitchenAid 4) until you have stiff peaks, about 10- 15 minutes.
Add the dry ingredients to the bowl and begin folding the ingredients together. Once everything is combined, continue folding until the batter flows slowly like lava.
Pipe macaron shells onto prepared baking sheets. Let the macarons dry until you can lightly brush the tops with your finger (30 mins for me). Bake for 22- 24 minutes, rotating halfway through. Gently poke shell, if it is firm, remove from the oven to cool. If they wiggle, add another minute or two.
Let the macaron shells cool on the sheet for 10 minutes before transferring them to a cooling rack.