* There are different types of hair dyes used in salons and sold in stores. For example, some are permanent and cannot be washed out with shampoo. Others wash out after a number of shampoos. The number of shampoos varies, depending on the product. Check the label to see about how long you can expect these colors to last.

Other kinds of dye:

* Progressive hair dyes change the color of your hair gradually. They make hair a little darker each time you use them.
* Henna is made from a plant and colors hair red or reddish brown.

No matter what kind of hair dye you use, follow directions carefully. Pay attention to all “Caution” or “Warning” statements.
What problems can hair dyes cause?

Some of the problems people have had from using hair dyes are:

* hair loss
* burning
* redness
* itchy or raw skin
* swelling in the face
* trouble breathing

Source: FDA