Colourless-sounding receptacle (4)
I believe the answer is:
pail
'receptacle' is the definition.
(thesaurus)
'colourless-sounding' is the wordplay.
'colourless' becomes 'pale' (similar in meaning).
'sounding' indicates a 'sounds like' (homophone) clue.
'pale' sounds like 'PAIL'.
(Other definitions for pail that I've seen before include "Water carrier" , "Cylindrical vessel" , "Open-topped container" , "A bucket as for water" , "water-carrier" .)