Gold reflected by pale ash (5)
I believe the answer is:
rowan
'ash' is the definition.
(I've seen this before)
'gold reflected by pale' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'reflected' says the letters should be written backwards (letters reflected back).
'by' means one lot of letters go next to another.
'pale' becomes 'wan' (wan can mean pale or grey).
'or' written backwards gives 'ro'.
'ro'+'wan'='ROWAN'
(Other definitions for rowan that I've seen before include "Mr Atkinson, actor" , "Tree with orange-red berry-like fruits" , "The mountain ash tree" , "ash native to mountain regions" , "Mountain-ash" .)