Grey hair is the 'in' colour and they've found the gene that causes it

EUREKA! They found it! No, not the cure for cancer. The grey hair gene. The IRF4, as it’s known to scientists. They already knew that this gene was connected with hair colour, but now they know that it is also the gene that causes hair to go grey.
The research was led by Dr Kaustubh Adhikari, a developmental biologist at University College London, after the heads of 6,600 people were examined. The volunteers were from Brazil, Colombia, Mexico, Peru and Chile, comprising of mixed European, Native American and African heritage. And guess what — they all came up with the same grey hair gene.