BLUE LAYER: In a medium bowl, dissolve blue jello in 1 cup boiling water. Stir in 1 cup cold water. Carefully spoon 2 Tablespoons of the liquid jello into each push-up pop container. Refrigerate for 1 1/2 hours or until firm.
WHITE LAYER: In a sauce pan, sprinkle unflavored gelatin over 1/4 cup cold water; let stand for 1 minute. Add the milk and sugar; heat over medium heat stirring until gelatin and sugar are dissolved. Let mixture cool for about 5-10 minutes. Whisk in sour cream and vanilla. Spoon 2 Tablespoons of the white gelatin mixture into each push-up pop over the blue jello. Refrigerate for 1 1/2 hours or until firm.
RED LAYER: In a medium bowl, dissolve red jello in 1 cup of boiling water; stir in 1 cup of cold water. Spoon red jello over the white layer. Refrigerate for 1 1/2 hours or until firm. Fill the remaining space in the push-up pops with cool whip and garnish with fresh blueberries.