Line two baking sheets with macaron mats. Prepare the piping bag with a 1 inch round piping tip. Set aside.
Using a food processor, pulse almond flour, confectioner's sugar, and meyer lemon zest into a fine powder mixture. Sift several times until there is little to no almond bits left.
In a bowl of an electric stand mixer fitted with the whisk attachment, add in the egg whites, granulated sugar and cream of tartar. Mix on medium-high speed until stiff peaks form (6-7 minutes). Drop in the yellow food coloring and add lemon extract and mix an additional minute.
Slowly add in the dry ingredients to the meringue. Fold with a silicon spatula and deflate the meringue by pressing it against the side of the bowl. Scoop the batter from the bottom until it is a smooth and shiny consistency (20-25 folds). Draw a figure eight with the spatula and if it folds back into itself within 15 seconds, batter is ready to be piped.
Put batter into the piping bag and pipe rings onto silicon macaron mats. Rap the baking sheets a couple of times on the counter to release any air bubbles trapped in the batter. Let the shells dry for 30-45 minutes or until a skin forms on the top. Preheat oven to 300°.
Bake the shells for 15-20 minutes or until the shells harden. Be sure to rotate the baking sheets half way through baking. The shells should easily peel off the silicon mat. Let them cool completely on the mats before removing.