Right after applying the color (5N, light brown), the color is darker than expected, at least one shade darker than the top of the box, and it has a hint of red/burgundy on my head. It darkened my medium brown hair with 30% grey a lot - the opposite effect of what I was going for. I was planning to bleach my hair in a few months, now bleaching the hair that dark is going to take twice as long. There was no smell during application and the application was easy. My scalp was a bit sore after, and I never knew my scalp to be sensitive before. I wish I divided the product in half as there is a lot of it in a single box, enough to color hair twice, even thick long hair like mine. Grey coverage is excellent. What I liked least was the pre-treatment shampoo used on my naturally dry hair. It says that he shampoo's purpose is to get rid of chemical buildup (in my case it would just be the ocean water leftovers), but I think what it really does is open the hair shaft. My hair was impossibly tangled and dry right after and it felt like straw. I only used half of the packet of the pre-treatment shampoo included on my long thick hair and it felt like it damaged my hair. It look a lot more than the hydrating shampoo/conditioner treatment to get my hair back looking healthy, but I managed with a lot of coconut oil, and other conditioners. I'm happy that this is a fairly clean product, and will try a dark blonde color instead next time, as I feel most let down about this permanent color being so much darker than advertised (5N).
