The most common and most likely answer to this crossword clue is the 5 plus 2 plus 1 plus 9 plus 6 letter word HORSE OF A DIFFERENT COLOUR
I've seen this crossword clue in Financial Times
H
O
R
S
E
O
F
A
D
I
F
F
E
R
E
N
T
C
O
L
O
U
R
Buddy explains!
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.