Add watermelon, 1 Tbs. lemon juice and 1 Tbs. sugar to a blender and puree until smooth. Remove foam at the top of the mixture. Carefully fill the molds about 2/3 of the way, leaving about 1 inch of room at the top of the mold. Add popsicle sticks and freeze for 3 1/2 hours.

Whisk to combine coconut milk and 1 Tbs. sugar. Let cool in refrigerator 30 minutes. Remove popsicles and layer coconut milk, about 1/2-inch. Reserve leftover coconut milk at room temperature. Return popsicles to freezer for 45 minutes.

In a blender, purée the following until smooth: blueberries, 1 tablespoon lemon juice and 1 tablespoon sugar. Strain mixture through a fine mesh sieve. Whisk in a few tablespoons of reserved coconut milk to lighten the color of the blueberry mixture. Place in refrigerator for 30 minutes before adding to the top of the popsicles. Return popsicles to freezer for about 1 hour. Unmold and serve.