Small stream carrying gold of dark reddish-brown colour (6)
I believe the answer is:
auburn
'reddish-brown colour' is the definition.
(I've seen this before)
'small stream carrying gold' is the wordplay.
'small stream' becomes 'burn' (I've seen this before).
'carrying' means one lot of letters go next to another (in a down clue, the bottom letters carry others).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'burn' put after 'au' is 'AUBURN'.
'of dark' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for auburn that I've seen before include "Golden" , "Name of Goldsmith's deserted village (6)" , "Dark coppery red" , "Goldsmith: 'Sweet . . . . . . loveliest village of the plain'" , "Copper" .)