To create coffee flavored jello: In a small bowl place the bags of gelatin and 4 tablespoons of cold water, set a side for gelatin to dissolve.
If coffee is cold, reheat it in a pot and add sugar (1/2 cup or to taste), stir to dissolve. Add gelatin to the coffee.
For the milk jello: In a small bowl, place the bags of gelatin and 4 tablespoons of cold water, set a side for gelatin to dissolve. Bring milk and sugar (1/2 cup or to taste) to a boil, in a small saucepan, stirring to dissolve sugar. Remove from the heat. Add gelatin mixture to milk and sugar, and stir to combine.
Use small glass cups and make thin layers of different flavor. Place jello cups in the fridge after each layer, to firm up. Keep both coffee and milk mixture in a room temperature, until your first layer is ready for the next one. Make sure the mixture is not hot, otherwise it will melt the first layer.
By making layers thin, it prettifies the dessert and adds a lot of flavor to each bite.