In separate bowls, mix the black cherry, lime, orange, and strawberry flavored gelatins with 1-1/2 cups boiling water each; let each cool to room temperature. In separate bowls, prepare the cherry, lemon, and orange-pineapple flavored gelatins with 1 cup boiling water; add 1/2 cup evaporated milk when each cools to room temperature. Add the room-temperature black cherry flavored gelatin to a 13x9-inch pan and refrigerate until chilled. Follow with a layer of the cherry flavor, lime flavor, lemon flavor, orange flavor, orange-pineapple flavor, and strawberry flavor, allowing each layer to cool before adding the next.