Hair Dye

Hair dye is a special type of chemical that is used to color the hair. It can be either permanent, semi-permanent or temporary. Hair dye is available for home use, but coloring can also be done by many hair salons.http://tlc.howstuffworks.com/style/hair-coloring.htm

While hair dye can be used to darken or change someone's natural hair color, it is also frequently used to cover gray hair or hair that has some gray strands present. However, some gray hair may also be resistant when it comes to absorbing permanent or semi-permanent dye and can take up to 45 minutes to accept the color properly.http://tlc.howstuffworks.com/style/hair-coloring5.htm

Permanent Hair Dye

Permanent hair dyes contain a developer or oxidizing agent and an alkalizing ingredient as part of their ammonia or an ammonia substitute. This allows the dye to raise the hair cuticle so the color can penetrate and allow the color to apply evenly.http://tlc.howstuffworks.com/style/hair-coloring2.htm

Temporary Hair Dye

The pigment molecules in temporary hair dye are large, which does not allow them to penetrate into the hair cuticle like a permanent dye. A temporary hair color can normally be washed out in one to two washes.http://www.brownskin.net/hairdyes.html Temporary hair dye is popular for Halloween and is normally sold in a spray to color the hair in a variety of natural and unnatural colors.http://tlc.howstuffworks.com/style/hair-coloring2.htm

Semi-Permanent Hair Dye

Semi-permanent hair dye has smaller pigment molecules than temporary hair dye, however it does not contain the developer that a permanent hair dye has. It is able to penetrate the hair cuticle, but will was out normally within eight to 15 washes.http://tlc.howstuffworks.com/style/hair-coloring2.htm

Beyonce, Jessica Alba - Loreal Commercial

Beyonce, Jessica Alba and other celebrities are shown talking about why they want to use Loreal hair color. They talk about the shimmering effect of their new color as well as the highlights, and a narrator states that the product is undiluted and contains two times the shine. Towards the end, each celebrity states that they get Loreal because they're worth it.