Hair dye...................?

how to know whether a hair dye penetrates or not?????

Hair dye...................?

"Contrary to what many believe, the hair dye does not penetrate inside your hair and replace the color inside your hair with a new color.

Hair is virtually impenetrable. Think about it: If hair were easy to penetrate, every time you wash your hair, take a shower, go for a swim, some water would get inside your hair and eventually replace the pigments inside it. Your hair would become colorless and transparent.

But that does not happen. Just look at any person with shoulder length hair. The hair ends are of the same color as the roots (at least if it is not dyed, of course). So the part of their hair they may have been wearing for two years has preserved the same color as the new growth has.

Indeed, hair dye essentially is paint. It covers your hair with a different color on the outside. And the lighter the dye the more transparent (or at least translucent) it is. Hence, the final result, which is nothing more than a visual illusion, is a visual combination of your natural hair color and the dye.

Because of this, you can always go darker. Even if you're naturally platinum blond, you can go all the way to goth, and it will work because the dark dye will completely cover up your natural color."

From answers2.com

Hope this helps!