Southern European capital, not against producing pigment (6)
I believe the answer is:
sienna
'pigment' is the definition.
(sienna is a kind of pigment)
'southern european capital not against' is the wordplay.
'southern' becomes 's' (abbreviation).
'european capital' becomes 'vienna' (capital of Austria).
'not' is a deletion indicator.
'against' becomes 'v' (abbreviation for 'versus').
'vienna' with 'v' taken out is 'ienna'.
's'+'ienna'='SIENNA'
'producing' acts as a link.
(Other definitions for sienna that I've seen before include "Earth colour, may be burnt" , "Medieval Tuscan city" , "Earthy paint pigment" , "Earthy colour" , "A shade" .)