Preparation:

Step 1:
In a large pitcher, combine the grape juice, lemonade, and cranberry juice. Stir well to ensure the flavors are thoroughly mixed.

Step 2:
Add the blueberry syrup to the mixture, stirring until well combined. This will give the drink a sweet flavor and enhance the purple color.

Step 3:
For a more vivid purple color, add 1-2 drops of purple food coloring and mix until the color is evenly distributed. This step is optional, as the natural juices may already provide a beautiful purple shade.

Step 4:
Fill a glass or mason jar with ice cubes. Pour the mocktail mixture over the ice, filling the glass about three-quarters full.

Step 5:
Top off the drink with sparkling water or lemon-lime soda for a fizzy touch. Stir gently to combine without losing the bubbles.

Step 6:
Garnish with fresh blueberries, a lemon slice, and a piece of purple rock candy for a whimsical touch. Serve with a fun straw or drink stirrer.