Line three baking sheets with parchment paper or silicone mats.
Sift together your powdered sugar and almond flour, twice. Set aside.
Whisk together the egg whites and granulated sugar in a heatproof bowl over a double boiler. Whisk for about 2 minutes, until the sugar dissolves. You can tell it is ready when you pull the whisk up and touch the mixture with your fingers, you shouldn't feel any granules. Do not let the bowl touch the water or it will cook the eggs.
Pour the mixture into the bowl of a stand mixer, fitted with the whisk attachment.
Whisk on low speed for 30 seconds, it should begin to foam. Increase the speed to medium for 2 minutes, until it becomes white and fluffy.
Increase the speed to medium-high, it should turn glossy and when you stop the mixer and pull the whisk out, you should have a stiff peak at the end of the whisk which only slightly bends at the end. This is how you know it is ready.
Pour in the powdered sugar/almond mixture as well as your vanilla and food coloring.
Gently fold them all together. Continue to fold and press the batter against the sides of the bowl. It is ready when it flows like lava from the rubber spatula, and you can make a figure 8 in the air without the batter breaking.
Carefully transfer the batter into a piping bag with a medium circular tip.
Pipe out 72 macaron shells, piping at a 90 degree angle. Once they have all been piped out, bang each tray twice on your counter. Use a toothpick to pop any remaining air bubbles. Sprinkle over your sprinkles.
Let them sit at room temperature for 30 minutes until they form a skin.
Preheat your oven to 325°F/162°C. Bake them one tray at a time for 15-17 minutes. Let them cool completely.