I started dying my hair due to grey when I turned 30. I stopped about a year ago at 40. The funny thing is that the amount of grey isn't that much more than it was then. 
I have noticed that the red hairs that I had, the ones that were always red regardless of time in the sun, have turned white more so than my other hairs.
I love it when women embrace their grey. All the pics here look great!
Living life like there's no tomorrow.
http://gorgebikefitter.com/
2007 Look Dura Ace
2010 Custom Tonic cross with discs, SRAM
2012 Moots YBB 2 x 10 Shimano XTR
2014 Soma B-Side SS