Instrument making some kaleidoscopic colours (7)
I believe the answer is:
piccolo
'instrument' is the definition.
(piccolo is a kind of instrument)
'some kaleidoscopic colours' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'PICCOLO' is hidden within 'kaleidoscopic colours'.
'making' is the link.
(Other definitions for piccolo that I've seen before include "Played, perhaps" , "Musical instrument - little (Italian)" , "Instrument (meaning "little")" , "Little flute" , "Shrill woodwind instrument" .)