In the context of currency exchange in Argentina, what's the etymology of "Blue dollar" exchange rates?
The US dollar isn't blue (it's green) and apart from "blue movies", I haven't heard of "blue" being used to mean illicit – usually it's black, or grey for less illicit.
Best Answer
From Spanish Wikipedia - Dólar blue:
Translation: According to some newspapers , the adjective "blue" is because transactions done with these bank notes are done on the black market to skirt the regulations established by the AFIP and, in English, blue color is also used to talk about something dark.