Black and brown plaid (6)
I believe the answer is:
tartan
'plaid' is the definition.
(I know that plaid can be written as tartan)
'black and brown' is the wordplay.
'black' becomes 'tar' (I've seen this in other clues).
'and' means one lot of letters go next to another.
'brown' becomes 'tan' (tan is a kind of brown).
'tar'+'tan'='TARTAN'
(Other definitions for tartan that I've seen before include "Distinctive pattern of a Scottish clan" , "chequered cloth" , "Pattern of the Scottish clans" , "Clan fabric" , "Cloth with a crisscross design" .)