I used to use the Revlon Colorsilk version that didn't have ammonia or some of the other chemicals (I think it was in a greenish box). I loved it, but I can't find it anywhere anymore. I guess they discontinued it and didn't ask me. 
After my daughter had a bad reaction to hair color at the salon, I decided to try to go as "clean" as possible, which is why I was using the Revlon verion I was. Lately, I've been using Madison Reed since I can't find the Colorsilk I was using. I like that it doesn't have ammonia, PPD (which I think is responible for a lot of the reactions), SLS, phthlates, or parabens. I realize that the best, most healthy option is to not color at all, but I'm not quite ready for that. And the Madison Reed is pricey ($30; it's also available at Walmart now), but I do feel a little better knowing that it doesn't have all of the chemicals in it. And I have never had any reaction problems to any hair color to this point, even though I know that anyone can have an allergic reaction to anything at anytime, even with the "clean" products.
Just my 2 cents worth. 