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