Brown finished report (3)
I believe the answer is:
dun
'brown' is the definition.
(dun is a kind of brown)
'finished report' is the wordplay.
'finished' becomes 'done' ('done' can be similar in meaning to 'finished').
'report' shows a homophone (sound like).
'done' sounds like 'DUN'.
(Other definitions for dun that I've seen before include "Dull greyish-brown colour" , "Dingy brown" , "press for money" , "Brownish gray" , "Pursue or badger for debt" .)