Against having deal turning green (7)
I believe the answer is:
celadon
'green' is the definition.
(I know that celadon is a type of green)
'against having deal turning' is the wordplay.
'against' becomes 'con' (as in pros and cons, for and against).
'having' means one lot of letters goes inside another.
'turning' indicates an anagram.
'deal' is an anagram of 'elad'.
'con' going around 'elad' is 'CELADON'.
(Other definitions for celadon that I've seen before include "pottery" , "Green" , "Greyish-green porcelain" .)