We use the term “curaçao” in this app to refer to orange liqueurs with a brandy or rum base. Blue curaçao should be the same, but the term is commonly used to refer to any orange liqueur with blue coloring. Why blue? No reason, really, except that the Bols company wanted to sell more bottles of the stuff, and added blue food coloring to move it off the shelves.
Tasty drinks require quality ingredients, and we don’t skimp here. We prefer blue curaçao from French brands like Giffard and Marie Brizard, as we’ve found they’re more likely to use real orange, and to bolster the flavor profile with touches of vanilla and other flavors.