Yellowish-grey (4)
I believe the answer is:
ecru
This clue is a double definition.
'yellowish' is the first definition.
(I've seen this in another clue)
'grey' is the second definition.
(I know that ecru is a type of grey)
(Other definitions for ecru that I've seen before include "Buff or beige" , "not whiter than white" , "Buff colour" , "natural colour" , "Raw linen colour" .)