Could have been a glitch.

I used to play with this when I had full sets in my invo, I just needed to activate the new color in the replay phase and it would mostly update midfight (sometimes it didn't happened), lots of work tho and I have 2 monitors lel. I'm guessing there is no item that does that, it would be... advertised a lot.

He was just changing hair colors every round theres no item that changes mid game