Preheat oven to 200 degrees. Place egg whites and sugar in a heat proof bowl which pairs with an electric stand mixer, and set bowl over a pot of simmering water.
Whisk mixture constantly until sugar dissolves and mixture is warm to the touch, about 3 minutes. Mix in salt and cream of tartar.
Transfer bowl to electric stand mixer, add in strawberry extract and whip mixture on medium-high speed until stiff, glossy peaks form and mixture has nearly cooled, about 7 minutes.
Meanwhile, using a small paintbrush, paint 3 vertical stripes of the gel food coloring (spaced fairly evenly apart) along the inside of a large pastry bag fit with a 1/2-inch round tip.
Fill pastry bag with meringue mixture (being careful not to smudge coloring with spatula while filling) and pipe 1 3/4-inch circles onto silicone baking mat or parchment paper lined baking sheets, spacing them 2 inches apart.
Bake in preheated oven for 1 hour and 15 minutes, until meringues are dry to the touch, while crisp on the outside and tender and soft on the inside (if you live in fairly humid climate or if you prefer them to be dry throughout you may want to bake them up to 20 minutes longer). Allow to cool and transfer to an airtight container.
Notes
*I did about 3 parts red to 2 parts maroon and mixed with paintbrush in a small bowl. Next time around I'd probably do more maroon, probably just 1:1 so they don't seem to look peppermint-y.