Clear a place in the refrigerator for a 9x13 baking pan.
In a small bowl, combine 1 cup of boiling water with 1 package of red jello. Mix well until evenly dissolved.
Pour into 8x8 pan and refrigerate for 1 hour or until firm.
Repeat for the box of blue jello.
Once jello is set, cut into ½" cubes.
Place cubes into a 9x13 pan and refrigerate.
In a mixing bowl, add ½ cup cold water and both packages of unflavored gelatin. Let set for about 5 minutes until thick.
Add 1-½ cups boiling water and stir until dissolved.
Stir in sweetened condensed milk.
Let set and cool until about room temperature.
Pour into 9x13 pan with jello cubes and return to the refrigerator to set, about 4 hours.
Cut into 2" bars and serve.