I am 56 and I really don't have much gray. Only a few errant hairs at my part, which I vigorously pull out. I was a natural blonde, whose hair was always many different colors. In fact, my mom was often accused of highlighting my hair when I was young! All of a sudden,when I was around 40, I realized I was no longer a blonde, but a light brown haired person, with some golden highlights. Did not like that at all. I had experimented with highlights in my early thirties, but didn't continue for a few years. So, I've been highlighting my hair for around 15 years. My hairdresser uses foils and it does not smell at all. I just cut my hair very short again (a pixie), which is flattering to me. So, I've had highlights with all lengths and styles. Frankly, I do not want to show any gray right now. I don't look good in silver, especially next to my face. It just washes me out. I have some deep laugh lines and I don't need anything making me look older while I am changing careers and looking for a job in 2011! Right now, most people I am working with think I am in my mid forties and I prefer to keep it that way, until I am no longer concerned about age discrimination. I think that just continuing to highlight as I have been will take care of most of the gray initially, especially, since my hair is short. Then, I will probably try the low lights.
Since my parents didn't really get gray until 65 or so, I have a while to worry.
Yes, I am vain, but, hey, I accept it.