The shade I used is 4-58 Dark Mahogany and my other two friends who tested it used 4-13 Dark Cool Brown and 4-54 Dark Copper Mahogany.
You can see a more specific review here, but what I'm going to talk about more are the purposes and advantages of this dye. First of all, the use of hyaluronic acid is something relatively new when it comes to hair dye. It is often used in skincare was it was just a matter of time until its benefits were transferred to hair. Basically it is a molecule that retains water, keeping the skin of your scalp hydrated.
Second of all, this hair dye is focused on giving the desirable color while protecting the hair. As you can see the colors are very natural. From what I have observed since I've dyed my hair with this hair dye, it is better from the one I had before. My ends don't seem so dry and my hair doesn't get oily so often. So, in terms of improving and protecting the hair, it does its job.
Also worth mentioning is that my mum used this and she was content with the coverage. She had a part of the roots already gray, but the dye worked its magic and turned them in a beautiful shade of mahogany.
This was a kindly reminder that skin and hair are not that different, they both need proper hydration so cheers to a glass of water. If you are decided to use a hair dye, make sure the color fits you and try to follow the instructions thoroughly.