I used dark brown last night. I've been dying my greys since my early 20's (15 years) and have used every dark brown on the market. My hair is medium thickness, and to my waist. I was unsure I would get good coverage with one bottle, as there didn't seem to be as much product in this bottle as other hair colors I've used. However, I was pleasantly surprised to find that although I didn't have enough to saturate all of my hair, the color is even! Also, I love the dark brown shade. It is by far the closest color I have ever come to my natural hair color. The product left my hair soft and shiny. The conditioner is amazing. I know this color grabs well because one finger nail is stained, and I still have dye on my skin around my hairline. Most colors have faded off my skin by the next day. I'm excited to see how long the color lasts as I wash my hair almost every day. I will use two boxes next time to really saturate every strand. I come from a family who owned hair salons, and I remember when my dad carried Vidal Sassoon products in his salons, years ago. Years later, you are still producing professional hair products. Thank you!