Burger King launched the Premium Kuro Burger (kuro means “black”) in 2012, colouring the bread with bamboo charcoal and adding squid ink to the ketchup. In 2013, the series upgraded to the Kuro Ninja, which kept the buns and squid ink ketchup and added on a slice of bacon. Now Burger King, will sell two more black burgers – the Kuro Pearl and the Kuro Diamond – both burgers feature the signature black buns, bamboo charcoal cheese, beef burgers made with black pepper and an onion and garlic sauce.