Translation:All three of them were wearing gloves and dark coats.
Excellent question. I put that nov23 14 and it wa accepted even though the primary correct translation was given as gloves and dark coats. If both are correct doesn't this mdan that there is a lack of precision in the Italian? For of course the two translations are actually different. Ie: In the primary translation the gloves could be sky blue
In English, it is also ambiguous: "dark gloves and coats" can mean both "dark gloves and dark coats" or "dark gloves and coats [of unknown shade]". If it were important to the writing, you'd want to specify "dark coats and dark gloves" or, for variation, "dark coats and black gloves". I imagine the same would be true in Italian: "i cappotti scuri e guanti neri".
As it stands, the sentence in both Italian and English is ambiguous as to the color/shade of the gloves.
Maybe because, without context, "coat" is a much more broad range of coat types - overcoat, raincoat, wind-breaker, mackinaw, formal jacket, etc. Unless the context indicates a specific kind of coat, you should stick with the generic translation. That's usually a good rule for translation in general.
Perhaps: "È freddo fuori; dammi il cappotto." "It's cold outside; give me the overcoat." I'm relying on on-line translators for reading "cappotto" as "overcoat", so a native speaker could help here.
There's also probably a phrase which means "overcoat", but I haven't encountered it, yet.
Yes it can. Indeed it is a better translation, because the standard interpretation of an adjective with conjoined nouns is that it modifes both; you give the English equivalent. From your question, I guess that Duo didn't like it. If so, report it.
To describe the coats only the Italian should either use a comma after guanti, or cappotti scuri e guanti.