The colour of one wrapped in explosive (4)
I believe the answer is:
tint
'the colour' is the definition.
(tint is a kind of colour)
'one wrapped in explosive' is the wordplay.
'one' becomes 'i' (Roman numeral).
'wrapped in' is an insertion indicator.
'explosive' becomes 'tnt' (TNT is an example**).
'i' going into 'tnt' is 'TINT'.
'of' is the link.
(Other definitions for tint that I've seen before include "A slight shade of colour" , "Shade; colour slightly" , "'Shade, tone (4)'" , "Quality of colour" , "work for coiffeuse?" .)