How Does Hair Colour Work?

I thought I'd take the time for clients who want to understand how colours work on a scientific level. I always like to know how and why things work technically, so here we start with a diagram:

The good news is that most hair colour products today have been been developed to new levels, for example using oil as a catalyst rather than ammonia, reducing the damage that can be caused by processing. Oil based colours can also cover grey! And most colour can be applied easily: some to wet hair, others to dry hair, worked into a shampoo-like lather, left to process. This depends on the nature of the service your colour requires.

LEVELS OF COLOURING:

• Level 1, semi-permanent colour ("Glans Farge")-- This product adds colour without changing natural colour dramatically. The hair colour contains tiny colour molecules that enter the hair's cuticle, or outer layer, and go into your hair's cortex. They don't interact with your natural pigments producing a nice "transparent" touch up to give the a hair a naturally "alive" finish.

• Level 2, demi-permanent colour ("Mini-Colour") -- This product level lasts longer than the previous. In this process, pre-colour molecules penetrate the cuticle and enter the cortex where they then partner to create medium-sized colour molecules. Their larger size means they take longer to wash out. These products do not contain ammonia so the natural pigment can't be lightened. However, it contains a small amount of peroxide, which allows for a subtle, but noticeable, colour enhancement.

• Level 3, permanent colour -- This is what you need for a more significant colour change (to go from black to blond, you'll still need to go with a process called double process blonding and it'd be wise to get this done professionally!!). In this level, tiny molecules enter all the way into the cortex, where they react and expand to a size that cannot be washed out. Your hair actually has to grow out over time. This product acts to lighten the hair's natural pigment to form a new base and then to add a new permanent colour. The end result is a combination of your natural hair pigment and the new shade you chose. That means the colour may appear different on you than on someone else using the same colour. (That's why sometimes a "strand test" is so important).

Hope this information has been helpful!! - Amin.