Prepare the First Layer: Dissolve one packet of gelatin in 1 cup of boiling water. Add 1/3 cup of cold water and stir. Pour into a serving dish or molds and refrigerate for 30 minutes until firm but not fully set.
Prepare the Second Layer: Dissolve the second packet of gelatin in 1 cup of boiling water, add 1/3 cup cold water, and mix well. Once the first layer is firm, gently pour the second layer on top. Refrigerate until set. Prepare the Third Layer: Repeat the process with the third gelatin flavor. Pour it carefully on top of the set layers and refrigerate until the entire dessert is firm.
Optional Decoration: After all layers are set, top with whipped cream or any other desired decoration.
Serve: Once the gelatin is fully set, slice and serve.