01 - Preheat the oven to 200°F. Line two baking sheets with parchment paper.
02 - In a grease-free mixing bowl, combine egg whites and cream of tartar. Using an electric mixer, beat on medium speed until soft peaks form.
03 - Gradually add granulated sugar, one tablespoon at a time, beating on high speed after each addition until stiff, glossy peaks form, about 5 to 7 minutes.
04 - Blend in salt and vanilla extract until just incorporated.
05 - Fit a piping bag with a large star or round tip. With a food-safe brush, paint one red stripe, one blue stripe, and leave one plain for white inside the piping bag.
06 - Gently spoon meringue mixture into the prepared piping bag, taking care to preserve the painted stripes.
07 - Pipe small, kiss-shaped mounds approximately 1 to 1.5 inches wide onto prepared baking sheets, spacing each mound about 1 inch apart.
08 - Bake for 1 hour and 15 minutes until the meringues are dry and crisp.
09 - Turn off the oven and allow the meringues to cool inside the oven with the door closed for an additional hour. Once completely cool, gently remove and store in an airtight container at room temperature for up to 5 days.