Blue butterfly, another name more famous, called butterfly bean flower, blue flowers are used by locals as natural dyes, cakes, staples, drinks are common. I didn't see this flower in the restaurant, I don't know if I didn't find it or not in bloom. Drinks a blue and a purple, in fact, when the up is blue, one of the cup squeezed some lemon juice, and then stirred, instantly purple. Personally feel purple more refreshing!