Black and blue balls ... settle down! (4,4)
I believe the answer is:
blow over
'settle down' is the definition.
'blow over' can be an answer for 'down' (thesaurus). I'm not certain of the 'settle' bit.
'black and blue balls' is the wordplay.
'black' becomes 'b' (abbreviation as in pencil classifications).
'and' is a charade indicator (letters next to each other).
'blue' becomes 'low' (both can mean sad).
'balls' becomes 'over' (I've seen this in other clues).
'b'+'low'+'over'='BLOW OVER'
Can you help me to learn more?
(Other definitions for blow over that I've seen before include "Fizzle out" , "Pass quickly and be forgotten" , "Cease to be a problem" , "Fade away without mishap" , "Die down without serious outcome, as storm may" .)