Add diced watermelon, lemon juice, vitamin C powder and 1 tablespoon honey to a blender. Purée until smooth.
Warm the watermelon juice mixture in a saucepan. Add gelatin and whisk to combine until the liquid is smooth.
Pour into silicon molds, about 3/4 of the way up, and freeze for an hour or until they are completely set. While those set, prepare the lime mixture.
In a small sauce pan, add the lime juice, food coloring and remaining honey. Stir to combine, and let simmer for 5 minutes. Remove from the heat, and sprinkle the gelatin over the lime mixture. Whisk constantly for 1 minute until all gelatin is dissolved.
Remove the set watermelon layer from the freezer and pour lime mixture over the top. Place back in the freezer for 20-30 minutes until completely set.
Tip: You can store gummies in an airtight container for up to 7 days.