Reddish-brown and gold stream (6)
I believe the answer is:
auburn
'reddish-brown' is the definition.
(synonyms)
'gold stream' is the wordplay.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'stream' becomes 'burn' (a burn is a small stream).
'au'+'burn'='AUBURN'
'and' is the link.
(Other definitions for auburn that I've seen before include "Of hair colour, reddish brown (6)" , "Goldsmith: 'Sweet . . . . . . loveliest village of the plain'" , "Dark coppery red" , "Shade of hair" , "Golden" .)