Back in the old days, when hair dyeing was in its infancy, hair color products routinely gave off a rather noxious rotten egg type of odour. It is good news then that today, the modern equivalents of these bygone products smell a whole lot nicer. The great thing about these present versions is that they are so much simpler to apply as well. Whether it be to wet hair or dry, quite a few of the colouring products available today can be worked into the tresses forming a shampoo like lather, left to work its magic (with or without a plastic hair covering piece, depending on the product) then rinsed out and conditioned. How simple is that?
Unfortunately, simplicity comes at a price, as is most often the case in life. Chemicals present in the hair dye, such as ammonia and peroxide, can be just as harsh and damaging to your curly hair today as were the chemicals in the early days of frizzy hair colouring, and this is especially true if you dye your hair too often. Obviously your hair is going to react differently to different levels of the chemicals found in various types of products, but generally there are three main types of hair coloring levels used by the main tresses product companies today- semi-permanent, demi-permanent as well as permanent.
Semi-permanent colour basically adds colour to the locks without changing the natural colouring too much. This kind of hair dye consists of tiny molecules that enter the hair through the cuticle but do not affect the hairs natural pigmentation. After several washes these types of hair dye cream, because they are so small , eventually exit the hair shaft leaving your hair as it was before the hair dyeing treatment. Semi-permanent hair dye usually lasts from six to twelve shampoos and has the ability to cover up to fifty percent of your greys. It enhances the organic colouring of your hair but doesn’t lighten it due to the fact that it contains no ammonia or peroxide.
Demi-permanent hair color usually last a lot longer than the semi-permanent variety, at around 22-28 shampoos. The pre-coloured molecules the actual hair through the cuticle, as in the semi-permanent dye however once in the hairs cortex they fuse with other substances to give medium sized colour elements. Because these compounds are larger in size, they now take that much longer to wash out of the tresses. Demi-permanent curly hair dye does not contain any ammonia so the natural skin discoloration of the curly hair cannot be lightened, but it does contain a small amount of peroxide which allows for slight (but noticeable) colour change.