Most people have gotten their hair dyed at some point in their life; however, many don’t know precisely how hair dye changes their hair’s color. There are several ways to dye your hair. Two of the most popular options include buying a box color from a store or visiting your local hair salon and having your hair professionally colored. Whether you opt for the use of chemicals or use hair dye without chemicals, there is still a science behind the coloring process.
There are Three Ways That Hair Color Works
Hair color can be broken down into three categories: temporary hair color, semi (or demi) permanent, and permanent dye. Each has its pros and cons; however, each will give you some level of the desired effect.
Temporary Hair Color
Temporary hair color lasts for a very short amount of time. It typically washes out in one to eight washes, depending on the type, and it fades rapidly. Temporary colors do not use chemicals such as ammonia or peroxide. Therefore, they are a popular trend for children and young adults.
Temporary hair color has large color molecules that enter the spaces between the hair cuticles. These molecules coat the surface of the hair, rather than penetrating it, and provide a short-term blast of color where applied.
Semi or Demi Permanent Hair Color
Semi (or Demi) permanent hair color has no ammonia but does have a little peroxide in the formula. The peroxide helps to tone the hair and helps to cover grays. While it is not intended for complete gray coverage, as it typically only covers about 30% of gray hair, it does help to hide them.
Semi-permanent hair color has small color molecules that penetrate each strand of hair. Because of this penetration, it can withstand up to 30 washes and fades gradually, eventually exposing the original hair color, including grays.
Permanent Hair Color
Permanent hair color is just that, permanent. Using small color molecules, permanent color penetrates every single hair cuticle and hair cortex.
The process causes a chemical reaction, with the help of ammonia and peroxide, and lightens, darks, tones, and covers 100% of all hair types, including grays.
Permanent hair color fades slowly over time, but will not wash out. The only way to change the color is to have it re-dyed or to grow it out; growing it out can take many months to years, depending on the length of your hair.
Re-Dying Your Hair
It is essential to know if your hair was semi-permanently dyed or permanently dyed. New dye, applied to semi-permanently dyed hair, may not absorb properly. While a stylist will know what they need to do to maximize the outcome of your new color, a novice can wind up with a shade of color they did not intend to have, such as orange or green.
The type of hair you have also makes a difference when re-dying your hair. If you have coarse hair, it takes more time to absorb all of the color in the dye. However, if you have fine hair, it takes less time for dye absorption to occur. This is important to be aware, as absorbing too much or too little dye can affect the outcome.
If you had your hair permanently dyed, and want to keep that color, you will want to have the roots touched up every 4-6 weeks, to avoid unsightly regrowth. Make sure you use the exact same color, or you will wind up with some very colorful locks.
Bleaches, Lighteners, and Highlights
Bleaches and lighteners, as well as highlights, enable you to dye your dark hair a blonde color. Using oxidizing and alkaline ingredients, the chemicals make the hair expand and pull in more color than it would without the chemicals. From there the natural hair pigments are dissolved, and the hair can be lightened. Doing this can significantly damage your hair, so be careful when experimenting with bleaches and lighteners. If you are unfamiliar with the process, you should consult a professional.
Condition for Protection
Your hair is continuously being exposed to damaging elements. Conditioners work to help protect against the damage of the sun, heat styling, chlorinated water, and many other culprits.