Dissolve half of a packet (1 tsp) of unflavored gelatin and a packet of Jello in boiling water. Dissolve the unflavored gelatin first, then add the Jello.
Pour the Jello mixture into the bottom of a 9x13 dish and refrigerate for 30 minutes to set.
Mix a packet (2 tsp) of unflavored gelatin to one cup of boiling water and dissolve. Add a can of condensed milk to the gelatin mixture and let it cool while Jello is setting in the refrigerator.
Pour one cup of condensed milk mixture and make sure it covers the Jello layer completely. Cool for 30 minutes in the refrigerator on a level surface.
Make a second batch of colored Jello and gelatin and let cool while the creamy layer is setting.
Pour the next Jello layer over the creamy layer, and cool for 30 minutes on a level surface in the refrigerator. Repeat until all layers of Jello and milk are set.
You will have to make a second batch of the condensed milk mixture halfway through. When the last layer of Jello is poured on top, allow the whole dessert to cool in the refrigerator for at least an hour.