Game’s to fix colour (6)
I believe the answer is:
russet
'colour' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'game's to fix' is the wordplay.
'game's' becomes 'rus' (rugby union).
'to fix' becomes 'set' (synonyms).
'rus'+'set'='RUSSET'
Can you help me to learn more?
(Other definitions for russet that I've seen before include "Brown with a reddish tinge" , "Autumn red" , "Reddish-brown - type of apple" , "Reddish-brown - not orange!" , "Brownish-red apple" .)