1. In a large mixer bowl, sprinkle gelatin over cold water and let stand until softened, about 5 minutes.
2. Meanwhile, in a small saucepan, combine sugar and 1/4 cup water. Stir over medium-high heat until sugar dissolves. Using a pastry brush dipped in water, brush down sugar crystals on sides of pan. Place a candy thermometer into mixture. Boil (do not stir) until syrup registers 238 degrees F (soft-ball stage), about 10 minutes. Pour into gelatin.
3. Using the whisk attachment, beat gelatin mixture on medium-low speed until slightly cooled, about 5 minutes. Increase speed to medium-high and beat to soft peaks, about 12 minutes. Stir in candy until combined. Tint with food coloring (if using). Use immediately.