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 sugar, one tablespoon at a time, beating on high speed until the mixture is glossy and stiff peaks form, about 5 to 7 minutes.
04 - Beat in salt and vanilla extract until just incorporated.
05 - Fit a piping bag with a large star or round tip. Using a food-safe brush, paint three stripes inside the bag: one red, one blue, and leave one plain for white.
06 - Carefully spoon the meringue mixture into the prepared piping bag, taking care not to disturb the painted stripes.
07 - Pipe small kiss-shaped mounds, about 1 to 1.5 inches wide, onto the prepared sheets, spacing them 1 inch apart.
08 - Bake in the preheated oven for 1 hour and 15 minutes, or until the meringues are dry and crisp. Turn off the oven and allow the meringues to cool inside with the door closed for 1 hour.
09 - Gently peel meringue kisses from the parchment and store in an airtight container at room temperature for up to 5 days.