Colour of zero scope (6)
I believe the answer is:
orange
'colour' is the definition.
(I know that orange is a type of pigment)
'zero scope' is the wordplay.
'zero' becomes 'O' (O resembles 0).
'scope' becomes 'range' (synonyms).
'o'+'range'='ORANGE'
'of' acts as a link.
(Other definitions for orange that I've seen before include "Dutch royal house" , "Royal house - fruit - colour" , "Loyalist colour" , "Kind of sauce" , "divided internally, naturally" .)