Curacao

Curaçao : 

A general term for orange-flavored liqueur made from the dried peel of bitter oranges found on the Caribbean island of Curaçao. 
Curaçao can be colored orange (known as Orange Curaçao or only Curaçao), blue (Blue Curaçao), green (Green Curaçao) or left clear (White Curaçao). All variants have the same flavor, with small variations in bitterness. Blue and green Curaçao are often used to provide color to mixed drinks.