Case of red, say, one put in case of brown (3)
I believe the answer is:
bin
'case of red' is the definition.
'bin' can be an answer for 'case' (thesaurus). I'm unsure of the 'of red' bit.
'one put in case of brown' is the wordplay.
'one' becomes 'i' (Roman numeral).
'put in' is an insertion indicator.
'case of' suggests removing the centre (like emptying a case).
'brown' with its middle removed is 'bn'.
'i' put within 'bn' is 'BIN'.
'say' acts as a link.
Can you help me to learn more?
(Other definitions for bin that I've seen before include "Household rubbish is placed in it" , "Storage receptacle" , "Domestic receptacle for rubbish" , "Waste container" , "Storage container" .)