Meanwhile, stir 1 drop green food color paste into another bowl, adding additional 1 to 2 drops green food color paste until well blended and desired light green color. Spread evenly over dark green layer; place in freezer 5 minutes. If remaining one-third of fudge mixture has set up, microwave uncovered on High 15 to 20 seconds or until stirred smooth. Spread evenly over light green layer. Sprinkle with candy sprinkles. Refrigerate until firm, about 2 hours. Cut into 8 rows by 8 rows.