In a food processor, pulse the almond flour and confectioner's sugar together for about 20 seconds, or until well combined.
Using the whisk attachment, whip the egg whites in a grease-free bowl of a stand mixer until foamy.
Add the granulated sugar to the egg whites, a little at a time and continue to whip on high until stiff peaks form. Do not over-whip.
Stop the mixer and add the food colour. Whip for a few more seconds until fully combined.
Remove bowl from mixer and sift the almond mixture onto the egg whites. Use a clean, grease-free spatula to fold the the mixture into the egg whites. Should be the consistency of molasses when ready.
Fit a piping bag with a 1.5" plain tip and fill the bag with the batter. Pipe small circles onto the parchment/baking mat.
Tap the pan on the counter a couple times to remove any air bubbles or peaks. Let the batter rest for about 30 minutes to an hour to allow a skin to form on the tops of the piped macarons.
While the batter rests, preheat the oven to 325ºF. Bake for 8 -10 minutes. Do not allow to brown.
(bake time may differ for your oven)
Remove from oven and allow to cool completely before assembling.