Nearly a colour match (5)
I believe the answer is:
agree
'match' is the definition.
(as in two tallies agreeing or matching)
'nearly a colour' is the wordplay.
'nearly' means to remove the last letter.
'colour' becomes 'green' (greening is a kind of colouring).
'a'+'green'='agreen'
'agreen' with its final letter taken off is 'AGREE'.
(Other definitions for agree that I've seen before include "Hold the same view" , "Give consent" , "get on" , "Say yes to a suggestion" , "Allow" .)