I started dying my hair maybe 6 months ago.  Before that I streaked it.  I researched products and ingredients using http://www.ewg.org/reports/skindeep/

I settled on use Herbatint  and bring it with me to my hairdresser.

When I have my nails done I bring my own nail polish.

Quoted from Arlene

I settled on use Herbatint  and bring it with me to my hairdresser.

just kind of curious why you chose Herbatint when it's rated at the Higher Concern level.

Quoted from Mrs_T_O+

I just started coloring my hair every few months last year at age 57 3/4.  I like the dark colors.  How dangerous is it?  I don't mind some gray showing, but decided finally to start coloring.  I kept putting it off & am glad I did.  Believe it or not, my former chiro suggested "Just for Men" & it works OK.  It fades with washing, not growth as they claim, but I have fine hair & it is geared for coarse hair.
How much danger am I in?
Mrs "T"    O+

There's enough connection between dark hair dyes and cancer, that it's worth the effort to research it a bit if you're going to dye your hair.  If I had time, I'd pursue some links, but it's my busy time of the year in my work right now.
You can click on that link I provided in an earlier post, which was just my Google for the general topic of risks involved in dark hair dyes, or something like that.

There are enough options that are non-carcinogenic, maybe you can get the desired results without risking your health.

You could also google natural hair dyes, or safe hair dyes, or something of that sort.

For someone who knows about henna, I'd like to know the answer to this:
I believe years ago, I was told that once you use henna, you cannot use any other hair colors, dyes, bleaches on your hair until it has completely grown out/ been cut out.  Does anyone know if this is true?

Quoted from pkarmeier

For someone who knows about henna, I'd like to know the answer to this:
I believe years ago, I was told that once you use henna, you cannot use any other hair colors, dyes, bleaches on your hair until it has completely grown out/ been cut out.  Does anyone know if this is true?

Pat, I've had lots of experience with henna, but I haven't dyed or bleached my hair since I was in college.  I don't know a time frame for waiting after henna before you can use dye, but just looking at it from a common sense standpoint, I would guess that there's some truth to the statement.
Henna does not dye the hair.  It is a cellophane-like substance that coats each hair shaft with little transparent plates similiar to the scales on a fish.  They seal the hair shaft, protect it and make it highly glossy.  Colored henna has natural plant dyes in the transparent plates that coat the outside of each hair, so the hair looks colored but it's only on the surface.
People usually re-apply henna about as often as you would hair dye.  If you stop using henna, it gradually washes away, over many weeks.  I can see how chemical dye would not penetrate the hair very well, if there's any henna still on the hair.

Thanks Victoria. Good explanation!