I got a lock of white hair on the top/front of my head when I was around 20. It’s still there. The first grey hair (on the temples) appeared around 35, hence 15 years after this early white lock.
I started going grey in my late 20’s or early 30’s. Now, my temples and sideburns are snow white. The rest of the hair on my head is still dark brown, though there are occasional grey hair mixed in. . .and a big bald spot on top!
My beard, which was once a marvellous chestnut red, is now more grey than anything else. I don’t mind. And I don’t color any of it.
I started getting pure white hairs at around 35. I’m 40 now and I’m probably 60% of this whiteness, even more in the old goatee. I’ll never color, just because I’m too lazy and not very concerned about it since I’m not in the market to replace my 40 year old wife with two twenties. 
Plus, I think it will be pretty cool to be completely ultra-white headed at 45.
Jammer
35 here and have never found one. Both my parents are pushing 70, and although they have some grey in their hair, neither are what you’d call grey-haired.
Last week. And I’m not happy about it. I’m 36 and my mom is 58 and she doesn’t have a single grey hair on her head.
I probably started getting my greys sometime ago, I’m not sure becuase I’ve been dying my hair various colors for the last 10 years. Last week, I was looking at my roots thinking it’s time to go in for color (tomorrow 12:30 appt - yay!) and noticed the grey. I will never go longer than 8 weeks on color again. I don’t want to know about my greys.
Been going grey since my teens. Haven’t started covering it, probably never will.
I noticed my first one when I was in fourth grade, so I was 9 or 10. That was the only one for a long time, then I started getting a few here and there my freshman year of college. By my senior year, I was developing streaks at my temples, so I’ve been covering gray since I was 22.
Mid teens, 16 or 17.
Never dyed my hair to hide it, but I have at various times been strawberrry blond, serious raging fire type redhead, purple, blue, green and multicolored for the hell of it=) Niftiest dyejob I ever had was a funky purple patterning put on by using a textured/figured paint roller over green, pattern was that ivy wall border. I liked it=) my hair was very long, down to my butt and it took my friend a long careful time of me not moving to lay on the purple rollered pattern, from crown of head to ends. I was a senior in HS and was in Midsummer Nights Dream as a fairie.
Today, actually. I thought I saw some a few weeks ago, and I made Cowboy put his glasses on and look. He said there weren’t any - could it be that he was lying to me? Where I found them today (and they’re definitely there) isn’t the same place that I thought I saw them though.
I’m 35, by the way, and I have no plans to color them. I’m tired of being the young one anyway.
In my late 20s, I noticed a white hair. I yanked it out. A patch of them grew in. Some years later, I began coloring, and now I get it touched up when it grows out a couple of inches. Some people prefer to see the white streak, but I don’t.
I think I noticed the first one, and it was in my beard, about at age 27. I tried coloring my beard once it got bad, because I have these two stupid and very ugly skunk stripes of gray in the beard. If it was just a nice salt 'n peppah I’d be fine with it.
Anyway, coloring didn’t work for anything, so I deal. Grecian for Beards is a joke, lemme tell ya…
Mid teens, not very many still (24) maybe two dozen or so, but more than my older brother and almost more than my father.
Must be all the stress in my life
I started going grey at 14. When I got married at 39, my hair was brown with lots of silver. On a whim, I tried a light brown Just For Men, just to see what it was like. It took off ten years. So I’m pretty much obligated to continue using it every couple of months. I’m 46, and I’m not ready to be, or look like, an old man yet. My whiskers and moustache are salt-and-pepper, so I usually apply some of the leftover JFM to my upper lip. Not too much or for too long, or I’d look like Wayne Newton!
I don’t mind *looking *like an old man, I just don’t want to start *acting *like one yet.
~20. And I started coloring in mid-late 20’s. I’ll probably stop somewhere around 50.
I’ve had grey hairs for the last five or so years now (I’m 20), but so far not in any quantity that would merit covering it.