Pros:
I like the foam, it makes it easy to apply. This is also the only brand I could find the color I wanted. I was looking for a warm black brown. Not a red black, not an ash black. I just wanted like a nice melted chocolate color only really dark. Idk why that was so hard to find. Because of that I will be using this brand again since the 3N is exactly what I wanted for color.... but....

Cons:
I bought 2 boxes the first time to color my whole head (my hair comes down just passed my shoulder blades), I really only needed one box. My hair started out roughly a level 4-5 split, 5 towards the ends, 4ish towards the roots. The first time I colored it, I had to leave it on for roughly 50 minutes (20 minutes passed the max amount) to achieve roughly color on the box. After about 2-3 weeks (washing about once per 3 days), that color had faded enough that you couldnt even tell my roots from the dyed area, and the ends were even lighter.
I just redid my whole head (again used only one box), and this time I did achive the dark color I wanted, but we will see how well it lasts.
Also during the first color, since I bought too much and had already mixed up the second box, my mom used up what was left to dye her roots (he hair is very close in color; she uses Loreal Excellence 4 Dark Brown). The John Frieda had awful grey covereage, and what it did cover had faded within juat 3 weeks. With the Loreal she has never experienced this.

Been using this for over 7 years and can no longer find It at WM, CVS, Target, sooo luckily I can buy on here, It's the only box hair color that works for ME, It's easy to apply, the color doesn't fade on me, I use 5n, doesn't fade on me, color stays TRUE, unlike others I've used before this the color would fade, turn reddish on me, THIS works PERFECT on me, I've used 4n when I wanna go little darker time to time but 98% Im 5n, I'm going to buy many to stock up lol I'm afraid they'll completely stop selling, I just hate when I find something that works on me they stop selling at stores, Thank goodness for Amazon ðŸ‘ðŸ¼ðŸ‘ðŸ¼ðŸ‘ðŸ¼ðŸ'‹ðŸ½

While I don't have grey hair, I had this annoying dirty blonde that was not my natural hair color. So I bought this hoping it would be a decent brown, and it went beyond my expectations! The process was easy and rinsing it out did not stain the bathtub!

I have medium brown hair, very thick and salt and pepper gray throughout. I followed the directions (didn't wash for 24 hours, don't shake the bottle, squeeze don't pump the foam out, etc) and had no issues. Color turned out great, better then I expected. I left it in an extra 5 mins since my hair is so thick and I have about 40% grey peppered in, I also used a shower cap and used a dryer to heat it up in the beginning to help it set a little better. My hair turned out a beautiful medium brown, where I had grays it is just a little lighter brown (almost golden auburn brown) and it looks professionally highlighted. I wouldn't say the foam concept is any better or worse then a cream or liquid, just different. It didn't stay foamy like I thought it would once I put it on my hair, but I made sure to cover everything as evenly as possible. I have short hair, so coloring is usually pretty easy and I don't have to worry about getting it even from root to tips.

Pros-
Went on easy, didn't smell as strongly as other dyes I've tried, covered my random gray hairs very well, and left my hair shiny and healthy looking.
Con- color(dark natural brown) was darker than on the box and made my already dark brown hair look almost black.