State of green sweater (3,6)
I believe the answer is:
new jersey
'state' is the definition.
(I know that New Jersey is a American state)
'green sweater' is the wordplay.
'green' becomes 'new' (I've seen this in another clue).
'sweater' becomes 'jersey' (I've seen this before).
'new'+'jersey'='NEW JERSEY'
'of' acts as a link.
(Other definitions for new jersey that I've seen before include "US east coast state" , "Recently-purchased clothing" , "change of clothing" , "Newark's state" , "Coastal US state" .)