Mix 1/2 of the package of orange jello and 1 envelope unflavored gelatin together in a small bowl. Add one cup of boiling water and stir until dissolved. Pour into a 13″ x 9″ x 2″ pan and put on a level shelf in the refrigerator for 15 minutes while you make the next layer. You will repeat this with each colored layer, alternating orange, white, purple, white, black, white, purple, white, orange.
White layers
In another small microwavable bowl put 2 packets of unflavored gelatin and 1 cup boiling water. Stir until dissolved. Slowly stir in the condensed milk until combined. This makes four 1/4-cup layers of white. When the first orange layer has solidified pour 1/4 cup of the white over the orange layer. Tilt the pan so that all of the orange layer is covered in a thin white layer. Return the pan to the fridge for 15 minutes to solidify. If the white liquid begins to solidify at any point you can put it in the microwave for 20 seconds at a time and whisk it to liquify it.
Black layer
The center black layer is made by mixing the small package of black cherry jello with 1 cup of boiling water and 40 drops of black food coloring.