Apologies, just catching up now.
I'm calling FARCE.... it is well documented that people with synthesia can sense colours when listening to music!!!
I therefore conclude it is a human sense!
Get my ace up.
https://en.wikipedia.org/wiki/Chromesthesia'They perceive colour alongside their normal auditory sensations.'
I mean the opening line of Synesthesia literally reads
Synesthesia is a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to involuntary experiences in a second sensory or cognitive pathway
It's not a sense itself and I really liked the answer
The very definition of a sense is the perception of a stimulus......
Sense:
'a faculty by which the body perceives an external stimulus; one of the faculties of sight, smell, hearing, taste, and touch.'
Colour is a sight, triggered by an external stimulus (sound).
It would make sense to view it as a sense surely