Line 3 baking sheets with silicone mats (circle template optional but recommended).
Place a medium sized round piping tip in a large piping bag. Twist the bag right behind the tip and add a clip to seal off the opening. Place the bag tip down into either a clean tall cup with the edges folded over the rim to keep the bag open, or clip it into a bag holder.
Using a kitchen scale, carefully weigh out and sift the confectioner’s sugar and almond flour into a medium mixing bowl. Whisk well to fully blend the two together.
Place egg whites, granulated sugar, and cream of tartar into a large mixing bowl, and begin beating with a whisk attachment using either a handheld mixer or a stand mixer for 2 minutes on a medium low speed (Kitchen Aid Speed 4).
Turn up the mixer to a medium speed (Kitchen Aid Speed 6) and beat for an additional 2 minutes.
Add 1½ drops of Americolor Violet Gel Food Coloring, and 3 drops of Americolor Sky Blue to the meringue.
Turn mixer up to medium high speed (Kitchen Aid Speed 8) and beat for 3 more minutes, or until peaks are very stiff and the meringue clumps up in a ball in the center of the whisk. Test stiffness by removing whisk and pointing it upward. Once large peaks can firmly hold their shape flipped upright, your meringue is ready.
Pour half of your almond flour/confectioner’s sugar mixture into the bowl with your meringue, and fold 15 times. One fold is equivalent to scraping all the way around the edge of your batter in your bowl, and then dragging your spatula through the middle. Be sure to scoop around the bottom of the bowl as well so you don’t miss any dry ingredients.
Pour in the remaining powdered sugar and almond flour, and continue folding only until the streaks of dry ingredients have disappeared, and then STOP. Do not continue folding as you normally would with macaron batter.
Divide batter equally among 3 bowls.
Begin preheating your oven to 295 degrees, using an oven thermometer to ensure accurate temperature readings.
With your first bowl, fold until the batter mostly settles back into itself when you wiggle your bowl back in forth. It is important not to over mix, so check your batter’s readiness every 5 folds or so at this point by scraping all batter down to the bottom of your bowl, and then wiggling your bowl back and forth several times. If the batter levels out with very few peaks and lines remaining, it should be ready.
Pour the batter from the first bowl into the prepared piping bag, and twist the opening off. Hold your bag at the twist between your thumb and pointer finger. Remove the clip.
Holding the piping bag straight up and down, apply pressure to begin piping your batter in the center of your circle templates, releasing pressure once you are a few millimeters short of your desired size. (For the macaron tower linked in the post, you'll need to pipe them just under 1.5 inches wide to make sure they won't be too large to fit in the tiers once they've settled after tapping your trays.) After you release pressure, use a small quick circular flick to release your tip from the piped macaron.
Once you’ve piped all of the batter from your first bowl with the lightest shade, use a wooden spatula to scrape down any remaining batter in your piping bag towards the piping tip to "clean" the lighter shade out, and pipe macarons until the batter is gone.
Once you've finished piping, firmly bang the tray on the counter a few times to pop any air bubbles and smooth out shells. Pop any remaining large bubbles with a toothpick.
To your second bowl, add ¾ drop Americolor Violet, and 1½ drops of Americolor Sky Blue and fold until batter mostly settles back into itself when you wiggle your bowl back in forth like mentioned in step 12.
Load your second bowl's batter into the same piping bag use for the first shade, and pipe your second tray repeating steps 13-16 with your medium blue shade.
To your third bowl, 1½ drops of Americolor Violet, and 3 drops of Americolor Sky Blue and fold until batter mostly settles back into itself when you wiggle your bowl back in forth like mentioned in step 12.
Load into the same piping bag and pipe your third tray repeating steps 13-16 with your third and final shade.
Set aside shells to dry until they form a skin and are no longer tacky to the touch. Once you can gently run a finger over your shells, they are ready to bake. Use a fan to speed up the process, rotating the tray every five minutes or so to ensure even drying. This usually takes at least 20 minutes for me even with a fan. (It may take much less time depending on the humidity of where you live)
Once shells are dry, and the oven has fully preheated to 295, place one tray in the center of the middle rack of the oven. Bake for 18 minutes.
Quickly open door to check the shell’s doneness by gently pressing on the side just above the feet to see if it’s firm. If it moves at all, bake for another 2 minutes.
Check shells again by performing the same test, pressing on the side. If they are still unstable, bake for one more minute, and check again. Repeat until shells are firm and do not budge.
Repeat baking process for the second and third tray, baking one tray at a time.
Allow shells to cool completely, and the carefully remove from silicone mat or parchment paper by gently peeling them off.