Prepare the bundt mold by washing and patting it dry. Set it aside.
Combine the konnyaku powder and granulated sugar in a small bowl. Mix well. Set aside.
Drain the pineapple cubes. Discard the syrup and set the fruits aside.
Drain the lychee syrup from the can into a measuring cup. Add water to the syrup until it reaches 950ml. Pour the measured liquid into a medium sized pot.
Add the sugar-jelly powder into the pot and cook it until the sugar and jelly is all dissolved. This should take approximately 10 minutes over low heat. Turn off the heat.
To assemble the pineapple lychee jelly, begin by arranging a layer of pineapple cubes at the bottom of the tin.
Spoon a layer of jelly into the bundt tin until the fruits are about two-thirds submerged in the jelly.
Let the jelly set, for about 3 to 4 minutes. To speed up the setting process, place the bundt tin in a larger tray filled with cold water.
While waiting for the jelly to set, add some yellow food coloring to the remaining jelly in the pot.
Once the first layer of the jelly is set, arrange another layer of pineapple cubes on the jelly. This is the final layer of pineapples. At this stage, you will not be using up all the pineapple cubes. You can use the remaining as a garnish or use them for other desserts.
Gently pour a layer of the yellow jelly until the 2nd layer of pineapple cubes are halfway submerged in the jelly solution.
Let the jelly set again. Once set, arrange the lychee fruits on it. At this stage, you will not be using up all the lychees in the can. You can reserve the balance for garnish or use them for other desserts.
Carefully spoon on the remaining jelly into the mold. Transfer the mold into the refrigerator and let the jelly set completely (for about 4 hours) before serving.
Turn the jelly out onto a serving plate. Add more pineapple cubes and lychees in the center if you wish. Serve the pineapple lychee jelly chill.