Benefits

• Temporary hair dyes are useful for people who are not sure about coloring their hair. They provide a great way to test a certain color. Not only this, but temporary hair dyes do not damage hair in the way that permanent ones will. Since they are meant to wash out, they do not make use of the same strong chemicals. This includes ammonia, which is often smelly in permanent hair dye.
  
  

Types

• There are many types of temporary hair dye. For a convenient option, choose a dye that washes into your hair while you are in the shower--like shampoo. You can also find them in the form of gels and sprays, which are easy to apply. Often, temporary hair dye can be purchased in individual sizes, perfect for those who just want to test a color once.
  
  

Function

• Temporary hair dye works in a different way than semi-permanent and permanent hair dyes. Due to the nature of temporary hair dye, there is no need for the color to penetrate the hair's cuticle. This means that they do not alter the natural color of the hair, and only coat the hair in a different color. This is what allows the color to be washed out so easily. This differs from the mechanism of permanent dye where the pigments enter and change the hair itself.
  
  

Warning

• Risk factors involved with any hair dye include the chance of an allergic reaction. Such reactions can cause rashes and swelling to the face. However, this risk is greatly reduced when using a temporary dye, as much fewer chemicals are used in the process. There is also the risk of creating an undesirable color result, though the nature of temporary dye means that it will soon wash out and is easily rectifiable.
  
  

Time Frame

• Application of temporary hair dye is typically a lot faster than permanent dye. It can be done easily at home and is often as simple as shampooing it through your hair, taking a few minutes. The length of time temporary hair dye stays in your hair depends on the individual product. Most products start to fade with the first wash, but can stay in your hair for a number of weeks (depending on how often you wash your hair). Check the label of the hair dye for a specific idea of how long it will last.