Liqueur Blue Curacao Castro. The Blue Curacao Castro liqueur is produced from 100% natural citrus fruitextracts, in a traditional way. It owes its name to the exotic Curaçao Island in the Caribbean. Its blue colour is reminiscent of exotic beaches. Its aroma and taste are due to the citrus fruit floating and being extracted in it. A surprising citrus fruit composition. It is an essential bar ingredient since it is mainly used for providing colour and aroma to citrus fruit based cocktails. You can enjoy it straight, on the rocks or in cocktails.