Color of unbleached linen (4)
I believe the answer is:
ecru
'color of unbleached linen' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ecru that I've seen before include "Natural stuff" , "Stange cure for a colour" , "off-white" , "Shade of unbleached linen" , "Raw linen colour" .)