In large microwavable bowl, microwave white vanilla baking chips uncovered on High 1 minute to 1 minute 30 seconds, stirring every 30 seconds, until smooth and melted.??Stir frosting into melted chips. Microwave uncovered on High 30 seconds or until mixture can be stirred smooth. Divide mixture evenly among 3 small bowls. Stir some green food gel into one bowl until well blended and desired color is reached. Spread evenly in pan; place in freezer 5 minutes.