Chill a hurricane or rounded cocktail glass. Add a little blueberry syrup around the inside of the glass and gently swirl it to create the purple marble effect.
Blend the colada base
In a blender, add coconut rum, pineapple juice, cream of coconut, heavy cream or coconut milk, and crushed ice. Blend until smooth and creamy.
Create the blue layer
Pour blue curaçao into the blended mixture and stir lightly, or pour it along the side of the glass so it creates blue streaks.
Pour and swirl
Pour the drink into the prepared glass. Use a spoon or straw to gently swirl the purple syrup, blue curaçao, and creamy colada together. Do not overmix; you want visible ocean-style waves.
Garnish
Top with whipped cream, blueberries, blackberries, and a pineapple wedge.