The dark or light colour of someones hair depends on how much melanin you have going on. Melanin comes in TWO delicious flavours: eumelanin, which is dark brown or black, and pheomelanin, which is reddish yellow.
As we get older, the pigment cells gradually die, which means less melanin, which means gray. BTW plucking doesn't help because once the cells are dead and they aren't going to start producing melanin just because you pull them out. You can't yoink your cells back to life, just like you can't yell someone back to life. Stop screaming.
It's genetic so if you've got a gray parent, you'll go gray. Why your parent is gray and your neighbour's parent isn't gray is a mystery. With all the money required to sew ears on to the backs of mice who has budget to figure out what makes some people salt and pepper heads. From the time that a person notices the first gray strands, it can take ten years or more to complete the process of complete hoariness.
M'kay. So I have at least 10 years.
So I have at least 10 years.So what about Marie Antoinette
You're right! She was sentenced and executed post-haste so what was up with Mary's coiff? Well...hair is dead no matter what and that means whiteness cannot travel back down the shaft - whiteness has to start at the root. This means that hair can only turn white as fast as it can grow. And there are no modern cases of anyone having a case of the overnight-whites due to stress. So when you look at it, the stress would have to be a stress caused by accidentally dropping a gallon of bleach on your head. That would be stressful. And it would turn your hair "white" but not really. Especially if you have dark hair. It goes yellow, not white. The yellow color you get from bleach is the natural colour of keratin, a protein in your hair.
So regular "going to get your head lopped off" kind of stress isn't enough to do it.
There are theories that Marie may have had a medical condition termed diffuse alopecia areata, which can result in sudden hair loss. (In maybe a few weeks.) For people who have a mix of dark and gray hair, the uncolored hair is less likely to fall out. So if she was salt and pepper to begin with it might have LOOKED like she went totally gray overnight. She was wearing a hat when they killed her anyway so WTF? It's probably just a rumor.
But if you ask me the stress of going gray is enough to make the process go faster. And unless you're THERE, unless you're finding more and more gray, you just don't know yet. You just don't know what it feels like. I say that because I've been there (back there in time) and said to someone who complained about gray hair "Oh, come on. It's distinguished." And now I can't get to the hair salon quickly enough.
How does that permanent colour thing work?
Most permanent hair colors use a two-step process (usually occurring simultaneously) which first removes the original color of the hair and then deposits a new color. You remove the colour with something like bleach or ammonia or hydrogen peroxide. It is an IRREVERSIBLE chemical reaction. That is why they call it permanent colour. The bleach oxidizes the melanin molecule rendering it colourless. Once the cuticle is opened with something like hydrogen peroxide, you can add colour. Because it's open. Pretty simple when you think about it. Alcohols and conditioners close the cuticle after coloring to seal in and protect the new color.
You'd have to wait for that to grow out so if you're sentenced to the guillotine, you can be certain you'll look your very best on d-day.
But why is gray hair wiry?
Hornification. Less antioxidants in there. Cell division. Increase in hair shaft diameter. Hair becomes wiry. Jesus, look it up. Do I have to explain everything?
Why am I blogging about this? Right. Paraphenylenediamine is supposed to be bad for you. But you know what? So is the stress of going gray.