In a small bowl, combine cranberry juice concentrate and 1 cup of the water. Pour mixture into a 1-1/2-quart baking dish. Combine orange juice concentrate and 1 cup water and pour into another 1-1/2-quart baking dish. In a third small mixing bowl, combine limeade concentrate, remaining 1 cup water, and green food coloring. Pour into a third 1-1/2-quart baking dish. Cover and freeze all dishes for 4 to 24 hours or until firm.

Break up ice mixtures slightly with a spoon. Scoop one-sixth (1/3 cup) of the limeade juice mixture into each of six chilled 8-ounce glasses. Scoop one-sixth (1/3 cup) of the cranberry mixture atop limeade mixture in each glass. Spoon one-sixth (1/3 cup) of the orange juice mixture atop cranberry mixture in each glass. Gently pour 1/4 cup of the lemon-lime carbonated beverage into each glass. Stir before drinking, if desired. Makes 6 servings.