Liver flushes and grey hair

Anyone know anything about hair reverting to original colour after a series of flushes?
I have a friend, now fifty, who's hair went grey when he was about thirty five. He's been alchoholic since his teens and had to have a liver transplant about two years ago. Within weeks of his transplant, the liver from which came from a nineteen year old accident victim, his hair reverted to his original colour.
Anyone know of anything similar? Tweet