Violet makes attempt to pursue popular detective (6)
I believe the answer is:
indigo
'violet' is the definition.
(indigo is a kind of violet)
'attempt to pursue popular detective' is the wordplay.
'attempt' becomes 'go' (go is a kind of attempt).
'to pursue' means one lot of letters go next to another.
'popular' becomes 'in'.
'detective' becomes 'di' (Detective Inspector abbreviation).
'in'+'di'='indi'
'go' put after 'indi' is 'INDIGO'.
'makes' acts as a link.
(Other definitions for indigo that I've seen before include "Violet-blue dye" , "I of ROYGBIV" , "Blue-violet colour" , "Sixth rainbow colour" , "Blue-purple colour in spectrum" .)