The origins of this offshoot product are murky. Some sources credit Bols, the Dutch spirits brand, with creating blue curaçao in the 1920s; others cite Senior Curaçao of Curaçao, a longtime orange liqueur distiller located on the island of Curaçao, as having been the first to “blue” a curaçao.

The product’s reputation, understandably, has been that of a gimmick — a staple of many a thatch-roofed beachside bar, but not really considered a serious cocktail ingredient outside of vacationland. One may recall that at the start of season 6 of “Mad Men,” a resort wear-clad Don Draper is served one of the quintessential cocktails of the blue curaçao canon, the Blue Hawaiian. When cocktail culture in America strayed toward the cloyingly sweet and kitschy, around the 1970s and ’80s, blue curaçao was along for the ride.