Start by heating your oven to 200°F and lining two baking sheets with parchment paper. Then, using your stand mixer or electric mixer, whip the egg whites and salt for about a minute until they are white and foamy. While the mixer is running, slowly add the sugar and continue to beat until stiff peaks begin to form. Then add the powdered sugar and peppermint extract and whisk to blend.
Prepare your piping bag by striping the inside with the red and green food coloring, then spoon the meringue into the bag. Pipe 1" rounds or larger "lollipops" spaced about an inch apart. If desired, sprinkle crushed candy canes on top.
Bake the meringues until they are dry but not golden, about 2 ½ hours. Then turn off the oven, leave the door open, and allow the meringues to cool for about an hour. Removed from the oven and store in an airtight container.
