Made better copper colour? (5)
I believe the answer is:
cured
'made better' is the definition.
(I've seen this before)
'copper colour?' is the wordplay.
'copper' becomes 'Cu' (chemical symbol).
'colour?' becomes 'red' (red is a kind of colour).
'cu'+'red'='CURED'
(Other definitions for cured that I've seen before include "Made healthy again" , "Freed of disease" , "Preserved by drying, salting or smoking" , "Healed - smoked" , "Made better or preserved" .)