Mix confectioners' sugar, milk and extract in small bowl until smooth. Stir in corn syrup until glaze is smooth and glossy. (If glaze is too thick, stir in small amount of additional corn syrup.) Stir in 3 to 4 drops food color until evenly distributed and glaze is smooth. Add additional drops of food color until glaze is of desired color.
To glaze cookies, place cooling rack on foil-lined baking sheet. Holding a cookie by its edge, dip the top of cookie into glaze. (Or spoon the glaze onto cookies using a teaspoon. Cookies can also be glazed using a new small paintbrush.) Place glazed cookies on cooling rack to dry. (The foil-covered baking sheet will catch any drips.)
Use contrasting glaze colors to decorate glazed cookies, if desired. Spoon small amount of contrasting glaze into small resealable plastic bag. Snip off tiny piece of the corner of the plastic bag. Create design by squeezing contrasting glaze onto cookies. Allow glazed cookies to dry thoroughly before stacking.