Fifty per cent dark in lighter country (5)

I believe the answer is:

sudan

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'country' is the definition.
(Sudan is an example)

I don't understand the remainder of the clue.

(Other definitions for sudan that I've seen before include "Recently-split country" , "African region" , "Country in NC Africa, capital Khartoum" , "African country on the Red Sea" , "Country between Egypt and Zaire" .)

I've seen this clue in The Telegraph.

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