The original Blue Curacao. Bols Blue was, and still is, the best-selling blue curaçao in the world. Known in the 19th century as “Crème de Ciel”, it is one of the oldest flavors in the current Bols catalogue. Bols Blue adds a sparkling blue color, a powerful orange flavor and a superb, unique and long-lasting taste to any cocktail. Being a great substitute for Triple Sec in cocktails like the Blue Margarita and Electric Lemonade, it is also delicious when served with carbonated water or orange juice.