Triple Sec and blue Curaçao may seem interchangeable, as the two flavored liqueurs are often lumped into the "tiki" category, but their differences outnumber their similarities.
Named after the Caribbean island Curaçao, blue Curaçao is an orange-flavored liqueur with an inexplicable blue tint and an alcohol by volume hovering between 15 and 25%.
The liqueur gets its flavor from the peels of Lahara oranges, which are inedibly bitter yet highly aromatic, thus imbuing the liqueur with a strong citrus flavor.
Apart from the gimmicky blue hue, blue Curaçao stands out for its noticeably bitter flavor with hints of vanilla and spices like cardamom or cloves which are added in production.
Likewise, triple sec is an orange liqueur, but the differences end there, as triple sec is clear, with a tart, sweet flavor and a more varied ABV range from 15 to 40%.
Triple sec is made from unripe orange peels distilled in beet sugar alcohol with plenty of beet sugar added to create a sweeter liqueur that's just as citrus-forward.
Triple sec has a more sophisticated, floral, citrus flavor that plays well with other spirits, and it's the go-to for citrus cocktails unless you want a bright streak of blue.