Such hair a golden stream? (6)
I believe the answer is:
auburn
'such hair' is the definition.
(hair colour)
'a golden stream?' is the wordplay.
'a golden' becomes 'au'.
'stream?' becomes 'burn' (a burn is a small stream).
'au'+'burn'='AUBURN'
(Other definitions for auburn that I've seen before include "Reddish-brown hair colour" , "Of hair colour, reddish brown (6)" , "Red-brown hair colouring" , "Copper" , "Golden" .)