This is a great product. I arrived at this product as I was looking for a dark brown/black colour without the chemicals associated with allergies as I am prone to skin related allergies. The colour itself is a lovely dark, rich black with some blue undertones but without that inky fake look that black hair dyes normally give. It looks totally natural on me. Leave it uncovered to develop the dark tones, cover with film to develop the warmer red tones. On the negative side, the rich dark colour fades quickly on my fine, wavy hair. I'd say it lasts about 8 weeks at most. My natural colour is a rich, very dark brown but has red undertones in the light which I want to cancel out. I only have a few greys so I can't really say how well it covers. I'm still giving a 5 because there isn't another product on the UK market that can rival this, at least, as far as I'm aware. Follow the directions on the website exactly, there is no need to grate the product, it just needs boiling water and to be left to stand before you mix it. Set aside an evening, and, yes, it's messy.