Changed colour drinking whiskey, but not crying (3-4)
I believe the answer is:
dry-eyed
'not crying' is the definition.
(I've seen this before)
'changed colour drinking whiskey' is the wordplay.
'changed colour' becomes 'dyed' (I've seen this before).
'drinking' is an insertion indicator.
'whiskey' becomes 'rye' (rye whiskey is a type of whiskey).
'dyed' placed around 'rye' is 'DRY-EYED'.
'but' is the link.
(Other definitions for dry-eyed that I've seen before include "Not crying" , "Unmoved" , "Without a tear" , "Tearless" .)