Horse with patches of white and brown (8)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
skewbald
(Other definitions for skewbald that I've seen before include "Marked with patches of white and a colour" , "maybe brown and white" , "(Horse) with white and coloured marks" , "patchy" , "Bicoloured creature" .)