In a medium mixing bowl, whisk together confectioner’s sugar, milk, vanilla and salt. Equally divide the glaze among 4 ramekins and add 2-3 drops of each color food coloring to each.
 
Use a teaspoon to dot a mixing bowl with high sides (that will fit a donut) with 1/3 of each colored glaze. Dip and twirl the top of 4 doughnuts into the “galaxy glaze” then place them on a cooling rack set over a baking sheet. Sprinkle with edible glitter/stars. Repeat dotting the glazes in the bowl, swirling and dipping the donuts into the mixing bowl, until all glaze is gone and all doughnuts are glazed. Allow to set for 10-15 minutes.