Many people in my life (myself included) often forget I was a science major in college. That's right, if you want to talk asymmetric boudinage or magma mixing, I'm your gal. Of course, I don't talk geology much in my daily life but my course of study is has maybe appreciate the scientific method.
I posted a couple weeks ago over my battle with grey hair and a lot of people recommended henna. And who says I don't listen to commenters! Initially I was a bit nervous about potentially making myself look bad (everyone's chemistry is different), but I found myself more excited in thinking of this whole thing as an experiment.
I know, how exciting are my Friday nights!
Coffee (apparently it helps the brown develop better then plain old water. You can also add things like lemon (to play up blonde) or olive oil (to make hair soft)
Paintbrush (optional but it does help get those harder to reach places)
Two short movies or one long one
2. Mix coffee with henna according to package directions. Notice the weird green color. Decide the "test portion" will be your entire head.
3. Put green gunk all over your head. Note: Make sure you are wearing an old dark T-shirt when you're doing this, or of course, you can go topless. Take your time and apply the gunk carefully with the paintbrush or your hands. Don't splatter henna all over your white bathroom. Secure whole situation with hair elastic. Cover head with plastic bag.
4. Watch a really long movie, in my case "The Women". The color needs to set for at least an hour. Tip: Might as well do all that other stuff you always mean to do like dishes or giving yourself a facial.
5. Once color is set (I waited an hour and a half) rinse in the sink, first with hot-water followed by cold water. Towel dry.
Results: Hair looks darker and grey is covered, feels gritty though (I am supposed to shower after but I'm going to wait until tomorrow morning). Smells like I've been in a pond all day.
At six dollars for a little pot of this henna stuff (I only used half of it), this is a pretty good bargain and it's all natural. But it does take a freaking long time.
Conclusion: Henna is a good way to cover gray hair if you have a lot of time and inclination to sit around your apartment with a plastic bag on your head. You may want to do some pre-color smell prevention though. Clearly though the most important conclusion is that the commenters on this blog know what they are talking about!