If someone has a strong kidney essence, hair is shiny, thick, strong and healthy and they will have fewer grey hairs when they are old. (chinaeducenter.com)
I certainly gained a fair few grey hairs over the years doing exhibition stuff, so I might leave it to a younger fresher generation, so I can just turn up and get drunk instead. (creativeboom.com)
The two cohorts may seem the same, give or take a few grey hairs, but they're not. (canadianbusiness.com)