Line a baking sheet with parchment paper. Lightly spray with nonstick cooking spray; set aside.

Wash apples and dry well. Remove stems; insert a wooden craft stick or cookie stick into stem end of each apple.

Combine sugar, corn syrup, and water in heavy medium saucepan. Cook and stir over medium-high heat until sugar dissolves. Clip candy thermometer to side of saucepan. Continue cooking for 7 to 8 minutes, without stirring, until temperature reaches 300°.

Remove from heat. Using a metal whisk, quickly whisk in food coloring gel. Dip apples, one at a time, into hot syrup mixture, tilting saucepan and turning apple to coat evenly. Allow excess mixture to drip off apple. Place on prepared baking sheet. Immediately decorate with garnishes, if desired. Let stand until set.