Instrument making some kaleidoscopic colours (7)
I believe the answer is:
piccolo
'instrument' is the definition.
(I know that piccolo is a type of flute)
'some kaleidoscopic colours' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'PICCOLO' can be found hidden inside 'kaleidoscopic colours'.
'making' acts as a 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" .)