Prepare a baking sheet by lining with parchment paper.
Place egg whites into the bowl of a stand mixer and beat until foamy. Add in the sugar and food color gel, continue to beat until soft peaks form and the egg whites are glossy.
In a separate bowl sift together the almond flour and confectioners sugar. Fold the almond flour mixture into the egg mixture until the dough makes a figure 8 when lifted with a spatula without breaking.
Fill a pastry bag fitted with a 1 inch tip with the macaron dough. Pipe the batter onto the prepared baking sheet into 1 1/2 inch circles. Once the baking sheet is full, pick it up and drop it a few times on the counter to release any bubbles from the batter.
Allow the cookies to sit out at room temperature for at least 1 hour before baking
Bake the cookies at 300ºF for 10-12 minutes until they are set and can be easily removed from the parchment paper.
Allow to cool before placing frosting in the center and sandwiching.
Notes
Use a printed template to make sure all of the cookies are the same size