At some stage, a metallic colour? (5)
I believe the answer is:
tinge
'colour?' is the definition.
(tinge is a kind of colour)
'at some stage a metallic' is the wordplay.
'at' is a charade indicator (letters next to each other).
'some stage' becomes 'ge' (I am not sure about this - if you are sure you should believe this answer much more).
'a metallic' becomes 'tin'.
'ge' after 'tin' is 'TINGE'.
Can you help me to learn more?
(Other definitions for tinge that I've seen before include "A slight shade of colour" , "A smack" , "Hint; shade" , "Slight trace; colour" , "Slight colouring" .)