Ammonia-free hair colour is a major trend in hair colour technology, and over past few years all the major hair colour brands have launched, or are launching, ammonia-free permanent colour ranges. So how do ammonia-free colours work and what does it mean for the health of your hair? In the past ammonia has been used in permanent hair colors to give better, more durable colors and allows for more significant color changes. Ammonia partially removes the natural colour from the hair. It opens up the surface of the strand so that the hair colour can get through and effectively lifts out the natural hair pigment so that the hair colour molecules can penetrate and deposit. Essentially, ammonia has been largely responsible for hair color’s ability to alter hair hue without washing out after only a few shampoos. This method of depositing colouring the hair has been commonly reported to have side effects…