Shevia is absolutely right - the more we see, the more others will view it as normal and beautiful, so the more people will go grey. He does amazing work. I have no artificial color in my hair, so my grey is coming in naturally, but I am pretty sure that even completely natural, my hair will never be as beautiful as he makes grey look!
FWIW, my mum started highlighting her hair when she started to grey and eventually she got to some light golden color that was so far removed from her natural color as to be unrecognizable. I told her that her hair was naturally black, and that I bet her natural grey would be gorgeous. She finally transitioned and sure enough, the steely grey is very similar to the photos linked here. It makes me wish my hair was naturally as dark as hers!