Shade provided by gold stream (6)
I believe the answer is:
auburn
'shade' is the definition.
(I've seen this before)
'by gold stream' is the wordplay.
'by' means one lot of letters go next to another.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'stream' becomes 'burn' (a burn is a small stream).
'au' next to 'burn' is 'AUBURN'.
'provided' acts as a link.
(Other definitions for auburn that I've seen before include "Shade of hair" , "Red-brown hair colouring" , "Dark coppery red" , "Of hair colour, reddish brown (6)" , "Copper" .)