Shade of unbleached linen (4)
I believe the answer is:
ecru
'shade of unbleached linen' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ecru that I've seen before include "Light fawn colour" , "Raw linen colour" , "Pale, creamy brown" , "Neutral colour" , "Greyish-yellow colour" .)