Grey-brown shade (5)
I believe the answer is:
taupe
This clue is a double definition.
'grey' is the first definition.
(I know that taupe is a type of grey)
'brown shade' is the second definition.
(I've seen this in another clue)
(Other definitions for taupe that I've seen before include "Fifty Shades of Grey must include this" , "Grey tinged with brown" , "shade" , "Grey-brown colour" , "Brownish-grey colour" .)