Victor beginning to go red (5)
I believe the answer is:
inner
'red' is the definition.
(I've seen this before)
'victor beginning to go' is the wordplay.
'victor' becomes 'winner' (synonyms).
'beginning to go' means to remove the first letter.
'winner' with its initial letter taken off is 'INNER'.
(Other definitions for inner that I've seen before include "red" , "Ring round the target bull." , "Target next to the bull's-eye on a dart board" , "Not a bad shot" , "Good shot at archery" .)