Envy's color (5)
I believe the answer is:
green
'envy's color' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for green that I've seen before include "part of the golf course" , "Ecological" , "Lacking experience (on the golf course?)" , "Unripe; envious" , "Immature" .)