FILLING: In separate greased 8-inch square pans, make each of the 3 flavors of Jell-O according to the directions on the package. When set, cut into 1/2-inch cubes. Dissolve lemon Jell-O in hot pineapple juice, then add 1/2 c cold water. Place in refrigerator until it starts to set. Whip cream. Fold crushed pineapple into whipped cream, then add semi-set lemon Jell-O. Fold in the Jell-O cubes and pour into crust. Chill about 1 hour before serving.