I am a stylist and have been using Inoa since it's launch in Feb.in Toronto , Canada. This is an amazing product, but it is very important to have a colorist that has been specially trained with this product. It is extremely important that it is mixed properly, and have the proper color choice. We were taught that Inoa appears to be a Shade  or two lighter because it is a more translucent color , apposed to the matte appearance of most permanent colors, including L'oreal's majirel. The product has to be DRY emulsified before rinsing and really rinsed well before shampooing with the Inoa shampoo. This stops all chemical reaction and gets all of the tint off the hair and scalp. This product works a little differently by having the color taken into the shaft by an oil delivery system ,ODS, and if this is done properly there is no reason for it to cause damage to the hair.
You also have to take into consideration that if you have previously chemically treated hair your results may vary. And one thing we also were trained to do was to analyze the client and their needs. Just because Inoa is the choice for one person it does not mean that there may be a better choice  of color for another person . L'oreal professional has at least six different lines of permanent and Demi permanent coloring available.
I hope this helps