Doppio and Red Eye Coffee are produced all around the globe. And they change according to region in where they are cultivated. So, the question arises what is Doppio and Red Eye Coffee's differentiating factor?In following section we will take a close look at what is Doppio and Red Eye Coffee color, serving style, types and much more. First thing to know is what are the different types of Doppio and Red Eye Coffee. Well, Doppio types include Espresso while types of Red Eye Coffee are NA.