Hair Coloring 118 has vastly expanded. The hair coloring business is very significant to cosmetic companies, with more than $7 billion in annual sales worldwide. It is also increasing in select markets such as China, India and Brazil at a rate greater than 15% per annum. The majority of consumers that color their hair do so for one of two main reasons. The first is to hide the appearance of gray hair. Natural hair is colored by insoluble pigment particles called melanin, either eumelanin (brown color) or pheomelanin (red color). As we age the production of these melanin pigments stops in selected strands, yielding white hair which in combination with the still pigmented strands gives the overall appearance of gray hair. This process generally starts at an age of 35 to 40 years and is often the trigger to start coloring hair with the aim of covering the gray and matching the original natural color. The second main reason for consumers to color is to transform their natural color into a more desirable color. This may be a shade that is more blonde, or darker, or to move to a new color or tone such as auburn or bright red. Thus, to meet the needs of all these consumers the range of shades available must be extensive and cover both the natural shade space from dark to blonde as well as a wide variety of tones including reds, blues, purples and golds. There is, therefore, a range of different products available for the consumer to choose from depending on the look they want to achieve. Several reviews of hair coloring are available1 so in the present examination the more recent advances in this product area have been highlighted. Hair Color Products To color hair we can chose between three processes. 1. Lightening (or lifting) the natural color by bleaching the melanin 2. Adding a new color to supplement the existing hair color by depositing dyes 3. Do both. Remove or lighten the underlying color and add a second color using dyes