Place egg whites in a stand mixer and mix on medium speed for 10 minutes; gradually add 5 Tbsp sugar. Add food coloring, if using.
While the mixer is going, blend almond flour and 1 c. sugar in a food processor. Add dry mixture to meringue once the 10 minutes is over.
Carefully fold drying ingredients into the meringue, about 50-55 folds. Batter should be oozing slightly but not too runny or stiff.
Place batter into the Decomax fixed with smaller round tip. Pipe batter onto each circle, tracing the smaller circle and filling in. Batter will ooze to fill out the larger circle.
Tap pan on the countertop to get rid of any bubbles and even out batter. Bake 15 minutes at 285°. Allow to cool before adding jam, buttercream, or ganache.
Macarons can be tricky. If you don't get them right the first time, don't worry! It's common for that to happen. Macarons are a trial-and-error treat. It may take a couple tries before you get them right.