What is the preparation of hair color?

Author: Rudolph Stamm  |  Last update: Monday, January 19, 2026

The preparation (dye precursors) is in the leuco (colorless) form. Oxidizing agents are usually hydrogen peroxide, and the alkaline environment is usually provided by ammonia. The combination of hydrogen peroxide and ammonia causes the natural hair to be lightened, providing a "blank canvas" for the dye.

What is the step by step procedure for hair coloring?

How to dye your own hair - a step-by-step guide
  1. Step 1: Make sure you have enough dye for your hair's length and thickness. ...
  2. Step 2: Read the packet instructions. ...
  3. Step 3: Split your hair into sections. ...
  4. Step 4: Apply the dye to your roots first. ...
  5. Step 5: Let your colour develop with your hair down.

What are the harmful chemicals in hair coloring?

Some harmful chemicals found in hair dye include ammonia, hydrogen peroxide, and parabens. These chemicals can cause scalp irritation, hair damage, and in some cases, allergic reactions. It's important to choose hair dye products that are free from these toxic ingredients for safer hair coloring options.

What should you not do before dying your hair?

Along with washing your hair right before dyeing it, avoid applying any styling products, like dry shampoo or leave-in conditioners.

Do I need to wash my hair before coloring?

The general rule of thumb is to not wash your hair the day of coloring or even the day before coloring if your hair washing routine allows. You might hear colorists say a second (or even third) day hair is best. Why is that so? Unwashed hair produces a natural oil protective layer.

Hair Color Levels (Numbers) Explained + Start A Formulation

Is it better to dye your hair when it's dirty or clean?

In conclusion, it is recommended to come to your hair appointment with clean hair but not freshly washed or wet hair. Communication is key, so don't hesitate to ask your stylist for their preference to ensure you get the best possible results.

How to prep hair before coloring?

You generally shouldn't shampoo immediately before coloring, because this will remove the natural oils that help protect your scalp during the coloring process. It's best to shampoo 12 - 24 hours before coloring when using semi-permanent or demi-permanent hair color. Shampoo 24 hours before using permanent color.

Can I dye my hair if I haven't washed it in a week?

While your hair should be clean for all hair coloring services, how clean may depend on the color you're going for. In most cases, having freshly washed strands is ideal—as Moore says, “hair color needs the path of least resistance” for the most seamless end results.

What is the rule in hair coloring?

A basic rule of haircolor is that cool (ash) tones neutralize warm (red or gold) tones and warm tones neutralize cool tones. Decide if it is too red, orange or yellow, then just choose the complementary tone that is opposite on the color wheel.

Should I color my hair wet or dry?

If your hair is healthy, meaning it's not fragile and damaged, technically, you can dye it when wet. However, we recommend coloring hair when dry so you achieve a look that aligns with your desired results.

What is the most damaging hair color?

Comparing Permanent, Semi-Permanent, and Demi-Permanent Hair Dyes. Permanent hair color has the greatest potential for hair damage due to the chemistry involved and should be done most cautiously.

What are bad hair dye brands to avoid?

Not Our Favorite Hair Dye / Hair Color Brands
  • Aveda (6 bad ingredients)
  • Calura (9 bad ingredients)
  • Clairol Nice'N Easy Color Crème (7 bad ingredients)
  • Clairol Nice & Easy Root Touch Up Semi-Permanent Colors AND Permanent Creme (7 bad ingredients)
  • Clairol Natural Instincts (6 bad ingredients)

Is hydrogen peroxide bad for your hair?

Hydrogen peroxide can damage the hair cuticle, the outer layer of your hair that protects and strengthens your strands. Damage to the cuticle can lead to reduced protection and make your hair vulnerable to breakage. In turn, that has the potential to result in hair loss.

Should you put a plastic bag on your head when dying hair?

After you've applied the color, cover your hair with plastic wrap, Gloria Swanson-style (a shower cap works well, too). Not only does this help the color penetrate better, but it prevents goop from streaking your forehead—and the bathroom sink.

What happens if you put grey hair dye on brown hair?

If your hair is brown, you may need to bleach it more than once before you apply the grey dye. It's important you get your hair as light as possible before you attempt to turn it grey – this will help ensure a more even tone and vibrant, all-over colour.

How do you prepare your hair for home dye?

So don't wash and dry your hair immediately before colouring it. Instead, go a day or two without shampooing or using hair styling products. Then, before dyeing, brush your hair so it's easy to section. That's how to colour hair at home for the best results.

What does 7 mean in hair color?

The level system is made up of 10 numbers which help determine the depth level of your natural hair. 1 is black, 5 is light brown, 6 is dark blonde, 7 is blonde and 10 is the lightest blonde.

When should you not use hair dye?

Some of the ingredients in hair dyes can cause serious allergic reactions in some people. Hair dyes can cause hair loss in some people. Some doctors advise women to avoid having their hair dyed during pregnancy (or at least until after the first trimester).

What does p mean in hair color?

P,C,S: Piano

Also known as Streak, distinct colors of hairs are mixed together. The name came from the dark and light colors that contradict each other like black and white keys of a piano. 2:1 or other ratios of hair colors are mixed in bundles on a weft. Although P usually represents Piano, C or S is used as well.

Is it better to have dirty or clean hair before coloring?

“Anytime you want to deepen your color or add lowlights, clean hair offers the most accurate read of your natural color,” she says. “This will allow your colorist the best match when determining the level of depth for your service.”

How long to leave hair dye in for grey hair?

Processing time with grey hair

The pigments in the dye need more time to penetrate through that so they can do their job. So with grey hair it's also best to let the dye sit for 45 minutes from the moment you've finished applying all of the dye so you'll be sure you have enough coverage.

Why do salons wash your hair after coloring?

Post-color washing is essential for maintaining the structural integrity of your hair. By cleansing and conditioning, salons help in closing the hair cuticles, locking in moisture, and preserving the smoothness of your locks.

What should I not do before dying my hair?

06 Skip shampooing before coloring.

Since shampooing can send some of these healthy oils down the drain, avoid cleansing for 24-48 hours before home hair coloring. The oils that you allow to build up on your hair during this time will protect your strands and keep them healthier post-color.

Do hair stylists prefer clean or dirty hair for coloring?

We can see your true hair color when your hair is clean—essential for color formulation. Lightening is more predictable when your hair is clean because it doesn't have to bust through oils and product buildup first allowing for even lightning throughout.

Is it better to dye your hair wet or dry?

"Semi-permanent and demi-permanent hair color can be applied to wet or dry hair, but wet hair application in not recommended for permanent hair color." Meanwhile, permanent color changes require a dry hair application. This could mean going lighter, or darker.

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