The Italian in California rejected shade (5)
I believe the answer is:
lilac
'shade' is the definition.
(lilac is a shade of purple)
'the italian in california rejected' is the wordplay.
'the italian' becomes 'il' (Italian for 'the').
'in' is an insertion indicator.
'california' becomes 'cal' (short for California).
'rejected' shows that the letters should be reversed in order.
'cal' reversed gives 'lac'.
'il' inserted inside 'lac' is 'LILAC'.
(Other definitions for lilac that I've seen before include "Syringa vulgaris, light purple in colour" , "Pinkish purple - shrub" , "Pale pinkish-violet" , "Plant" , "Purplish in colour" .)