Black cats around add colour for a western town (9)
I believe the answer is:
tombstone
'a western town' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'black cats around add colour' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'cats' becomes 'toms' (tom is a kind of cat).
'around' means one lot of letters goes inside another.
'add colour' becomes 'tone' (I can't justify this - if you can you should believe this answer much more).
'b' going into 'toms' is 'tombs'.
'tombs'+'tone'='TOMBSTONE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for tombstone that I've seen before include "Last monument" , "Does it display departure date" , "film location" , "Graveyard marker" , "Memorial in churchyard - town in Arizona" .)