In the bowl of a stand mixer fitted with the paddle attachment, beat confectioners’ sugar and meringue powder at low speed until combined. Slowly add ⅔ cup (160 grams) warm water, vanilla, and salt, beating until fluid, about 1 minute. Increase mixer speed to medium, and beat until stiff, 4 to 5 minutes; add up to 2 tablespoons (30 grams) warm water, 1 teaspoon (5 grams) at a time, until icing is desired consistency.

In a medium bowl, reserve three-fourths of icing (about 4½ cups or 843 grams). Divide remaining icing between 2 small bowls; tint each with food coloring as desired. Store, covered, until ready to use.