Fine fabric that looks best green (4)
I believe the answer is:
lawn
I believe this clue is a double definition.
'fine fabric' is the first definition.
(I've seen this before)
'that looks best green' is the second definition.
(as in a lawn outside a house)
(Other definitions for lawn that I've seen before include "Garden feature" , "Grassy expanse" , "Fine cotton or grass garden" , "Fine woven cotton" , "Smooth grass area, often in front of house" .)