Never wrong about European's superficial appearance (6)
I believe the answer is:
veneer
'superficial appearance' is the definition.
(I've seen this before)
'never wrong about european's' is the wordplay.
'wrong' indicates an anagram.
'about' is an insertion indicator.
'european' becomes 'e' (abbreviation e.g. EU).
'never' anagrammed gives 'vener'.
'vener' enclosing 'e' is 'VENEER'.
(Other definitions for veneer that I've seen before include "Thin surfacing of wood" , "Superficial veneer" , "Thin coating on the outside" , "Thin skin on surface" , "Superficial shine" .)