In a medium bowl, beat the egg whites, salt, vinegar, extract and food coloring on medium speed until soft peaks form. Gradually add sugar, 1 tablespoon at a time, beating on high until stiff glossy peaks form and sugar is dissolved, about 6 minutes.
Drop by rounded teaspoonfuls 2 inches apart onto parchment lined baking sheets. Sprinkle with pink crystals if using.
Bake at 250º for 40 to 45 minutes or until firm to the touch. Turn oven off. Leave meringues in oven for 1 to 1 1/2 hours. Remove cookies to a wire rack, cool.
Store in a airtight container.
Notes
*When making meringue cookies, use gel food coloring. Gel food coloring won't add extra moisture to your egg white.*