Combine the crumbs, sugar and butter; press onto the bottom of a 13-in x 9-in. x 2-in. greased pan. Chill. Combine lime gelatin and 1-1/2 cups boiling water; stir until gelatin is dissolved. Pour into an oiled 8-in. x 4-in. x 2-in. loaf pan; chill until very firm. Repeat for strawberry and orange gelatins. Soften the unflavored gelatin in cold water. Boil pineapple juice; stir into unflavored gelatin. Set aside until slightly thickened. Place whipped topping in a large bowl; gently fold in pineapple juice mixture. When flavored gelatins are firm, cut into 1-in. cubes; gently fold into whipped topping mixture. Spoon over crust. Chill for at least 2 hours.