Equine color (4)
I believe the answer is:
roan
'equine color' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for roan that I've seen before include "Nora (anag) - horse" , "Two-colour horse" , "nag" , "Horse with a brownish coat sprinkled with grey" , "(Horse) white-sprinkled coat" .)