Synesthesia is something that is pretty interesting. The ability to have the brain give you a different response to a stimulus that should not have happend is cool on its own even better when you look into it. https://elemental.medium.com/seeing-sounds-what-its-like-to-live-with-synesthesia-fcec02831a1 there are a lot of interviews with people who have this. This is just one article on it. A quick YouTube search will throw more. https://synesthesia.com/#/Task/0/0/gateway-synesthesia-test-synaesthesia-test-quick-version/1011 and this is a test to take to see if you have synesthesia.
The brain having multiple responses means that you have the ability to taste or hear a color. Something that a regular person can not. That then asks the question does blue sound the same to everyone? I'm not sure if anyone has looked into that but the idea is cool.