Prepare for painting buff and blue (3,4)
I believe the answer is:
rub down
'prepare for painting' is the definition.
I can't judge whether this definition defines the answer.
'buff and blue' is the wordplay.
'buff' becomes 'rub' (I've seen this in another clue).
'and' says to put letters next to each other.
'blue' becomes 'down' (both can mean sad).
'rub'+'down'='RUB-DOWN'
Can you help me to learn more?
(Other definitions for rub down that I've seen before include "Drying - cleaning - grooming" , "Act of drying, smoothing or cleaning" , "Vigorous towelling" , "Get ready to paint" , "Prepare eight ac with sandpaper, say" .)