There is no standardized definition of different degrees of roast, coffee are seldom truly light-roasted. Should be noted that Turkish coffee is not dark-roasted.
Light This roast is used only for extremely good-quality delicate or high-grown arabicas. The American version of this roast, "Cinnamon", is so called because of the color of cinnamon bark. Sometimes called "half-city" or "New England" roast. It is high in acidity and low in body.
Medium "American roast" or possibly "city" if slightly darker than medium. Sometimes called "regular" or "brown" as dark as possible with no oil surfaces.
Viennese Or "light French" or "full city", an American term meaning slightly darker than medium roast. This roast is speckled with dark brown spots and a bit of oil on surfaces.
Dark "Spanish"; "Cuban"; there may be some oil on bean surfaces, "deep roast"; French roast.
Continental Can olso be referred to as "double roast"; "high"; in America, "French roast" and "European". With a nearly bitter chocolate coloring, this roast is variously described as very dark; dark French, heavy and Italian.
Italian In America, darker than in Italy; may be called "espresso" roast (or may not); almost black and very oily; the predominant taste is the roast rather than the coffee.
In America all roast are becoming darker, probably because of the emphasis on espresso and espresso-based drinks, which are seen to be the height of sophistication. In fact, in many other countries as well, there are those who think the goal of all roasting is to make the coffee taste pleasant and balanced even if this involves suppressing the more unique and unusual flavors. It must be remembered that dark roasts were originally designed to hide the flaws of inferior coffees, and to bring out the best in cheap blends loaded with inferior tasting robusta.