Place all ingredients except food coloring in the top of a double boiler over simmering water and heat, stirring, until sugar dissolves and mixture is smooth.
Do not allow water underneath to boil or icing will not be glossy.
Tint with food coloring as desired.
Spoon over Petits Fours or any small cakes set on wire racks over baking sheets.
Scrape up run-over from baking sheet, return to double boiler, and warm again until of pouring consistency.
If thick, add a few drops warm water.