Restrained method of painting walls of temple (9)
I believe the answer is:
temperate
'restrained' is the definition.
(similar in meaning)
'method of painting walls of temple' is the wordplay.
'method of painting' becomes 'tempera' (type of painting).
'walls of' suggests removing the centre (only the edge letters remain).
'temple' with its centre taken out is 'te'.
'tempera'+'te'='TEMPERATE'
(Other definitions for temperate that I've seen before include "Moderate, mild" , "Restrained" , "Controlled" , "Calm" , "With mild climate" .)