To use hair dye at home safely, follow three rules: pick a shade close to your natural color, do an allergy test 48 hours before every application (even with a dye you have used before), and follow the pack instructions exactly. Below: shade numbers, dye types, the steps and aftercare, with picks from L'Oréal Paris and Garnier.
Quick answer
- Do an allergy test at least 48 hours before every dye job, and do not dye if you get redness, itching, swelling or burning.
- The first number on a dye is the depth level, from black to lightest blonde; the number after the dot is the tone.
- Stay within 3 shades of your natural color, because big lifts need stronger peroxide, which damages hair more.
- Ammonia-free dye can still be permanent and needs an allergy test like any other dye.
- Never use hair dye on your eyebrows or eyelashes; it can harm your eyes.
How do you do an allergy test before dyeing your hair?
An allergy test is a must before every dye job. The NHS advises testing at least 48 hours before you dye, and the US Food and Drug Administration (FDA) says to test every time, because people can develop sensitivities with repeated exposure, even if a dye never caused problems before.
Allergy test steps
- Follow the test method in the pack: mix a tiny amount and apply it where directed, usually behind the ear or inside the elbow.
- Also try the dye on a small strand of hair to see the real result.
- Wait 48 hours without washing the area, and watch the skin throughout.
- If you notice redness, itching, swelling, burning or a rash, do not use the dye, and see a dermatologist for allergy testing, as the American Academy of Dermatology (AAD) recommends.
Why the test matters
Many permanent and some semi-permanent dyes contain paraphenylenediamine (PPD), the ingredient most often linked to hair dye allergies. The NHS notes that symptoms can take up to 72 hours to appear and include stinging, burning, an itchy rash, dryness and blisters. A past black henna tattoo raises your risk, because black henna paste contains high levels of PPD.
When to get help straight away
If you react while dyeing, wash your hair and scalp with a mild shampoo immediately. If your lips, tongue or throat suddenly swell, or you struggle to breathe, call an ambulance.
How do you read hair dye numbers?
A shade number has two parts: the first number is the level (how dark or light), and the digits after the dot or slash are the tone (the color reflect). Always check the shade chart on the pack.
The first number: level
- 1: black, such as Garnier Color Naturals Black No. 1.
- 3, 4, 5: browns from dark to light, such as Garnier Color Naturals Dark Brown 3.
- 6, 7, 8: blondes from dark to light.
Digits after the dot: tone
- 0: natural, no reflect; usually best for gray coverage.
- 1: ash, which cools warmth and brassiness.
- 2: violet or pearl.
- 3: golden.
- 4: copper.
- 5: mahogany.
- 6: red.
For example, L'Oréal Excellence Creme 6.1 is dark blonde (6) with an ash tone (1). A repeated digit means a stronger tone, so Garnier Olia 6.60 Intense Red is dark blonde with intense red. A second, different digit adds a softer secondary tone, as in Garnier Olia 4.26 Red Violet.
What is the difference between permanent, semi-permanent and ammonia-free dye?
Permanent dye changes the color inside the hair and does not wash out; semi-permanent dye fades gradually with washing; temporary color lasts only until your next wash.
Permanent dye
It is mixed with a developer (hydrogen peroxide), which lifts the hair slightly and locks color inside, giving the best gray coverage. Examples include L'Oréal Excellence Creme 7.17 Ash Blonde, with full gray coverage and triple care, and Garnier Color Naturals Brown No. 4, enriched with olive, avocado and shea.
Ammonia-free dye
Ammonia opens the hair's outer layer so color can enter, and it smells strong. Ammonia-free dyes use other ingredients and smell milder, but many are still permanent. Examples: the ammonia-free L'Oréal Oil Permanent Hair Color 6.0 Dark Blonde, Garnier Olia 4.0 Dark Brown with gray coverage, and Garnier Olia 3.0 Soft Black. Remember: "ammonia-free" does not mean "allergen-free", so the 48-hour test still applies.
Temporary root spray
To hide gray roots between dye jobs, the L'Oréal Magic Retouch Black Root Spray 75ml covers roots instantly and lasts until the next wash.
What is the best brown hair dye?
The best brown is the shade closest to your natural color; levels 3, 4 and 5 cover most needs. The AAD notes that darker dyes are generally gentler on hair than lighter ones.
- Natural dark brown: Garnier Color Naturals Dark Brown 3, a rich shade with gray coverage.
- Shiny light brown, ammonia-free: Garnier Olia 5.0 Light Brown.
- Brown with a warm touch: L'Oréal Casting Crème Gloss 415, rich color with shine.
- Powder dye: Bigen Hair Dye Powder Dark Brown from Bigen; there is also Bigen Black, described as ammonia-free.
How do you dye your hair at home, step by step?
- 48 hours before: do the allergy test and strand test.
- Prepare: the gloves in the pack, an old towel, a timer, and a rich cream along the hairline and ears to avoid staining.
- Dye dry, unwashed hair unless the pack says otherwise.
- Mix exactly as directed and add nothing else.
- Start at the roots for gray coverage, then spread through the rest.
- Set a timer: never leave dye on longer than directed, as the FDA stresses.
- Rinse well: rinse hair and scalp until the water runs clear, then apply the conditioner in the pack.
The FDA also warns to keep dye away from your eyes and never to dye eyebrows or eyelashes, which can hurt the eyes and even cause blindness.
Professional dyes
Dyes such as Wella Koleston Blue Black 301/0 from Wella and L'Oréal Professionnel INOA 5 Light Brown from L'Oréal Professionnel are sold without developer, which is chosen by the lift needed, for example Wella Welloxon 9% Developer. If you are not experienced with these ratios, let a salon professional use them.
How do you care for colored hair?
Colored hair is drier and needs a gentle shampoo, conditioner after every wash, and sun protection. The AAD notes that sun can leave hair weak, dry and faded, especially after dyeing, and suggests a wide-brimmed hat.
- Use a color-care shampoo such as L'Oréal Vitamino Color Shampoo 500ml, which cleanses gently and helps color last.
- Follow with L'Oréal Serie Expert Vitamino Color Conditioner 750ml.
- For dry ends, try the L'Oréal Elvive Hydrating Serum Spray 150ml with hyaluronic acid.
To pick a shampoo for your hair type, see our best shampoo by hair type guide, and for a weekly oils-and-masks plan, our step-by-step hair care routine.
Comparison of hair dyes available
| Product | Brand | Best for | Key feature |
|---|---|---|---|
| L'Oréal Excellence 7.17 Ash Blonde | L'Oréal Paris | Cool blonde | Full gray coverage, triple care |
| L'Oréal Excellence 6.1 Dark Ash Blonde | L'Oréal Paris | Cool dark blonde | Full gray coverage |
| L'Oréal Oil Permanent 6.0 | L'Oréal Paris | Avoiding ammonia | Oil-based permanent, no ammonia |
| Garnier Olia 4.0 Dark Brown | Garnier | Dark brown | Ammonia-free, gray coverage |
| Garnier Olia 5.0 Light Brown | Garnier | Light brown | Natural shine, ammonia-free |
| Garnier Color Naturals 3 | Garnier | Natural dark brown | Nourishing oils |
| Garnier Olia 6.60 Intense Red | Garnier | Bold red | Intense color and shine |
| Bigen Powder Dark Brown | Bigen | Powder fans | Gray coverage |
| L'Oréal Magic Retouch Black | L'Oréal Paris | Temporary root cover | Lasts until next wash |
| L'Oréal Vitamino Color Shampoo | L'Oréal Professionnel | Aftercare | Helps color last |
How to choose the right hair dye: a practical checklist
- Define your goal: gray coverage, a subtle change, or hiding roots temporarily.
- Know your natural level and stay within 3 shades of it.
- Pick the tone: ash cools brassiness, golden and copper add warmth, and natural (0) is best for grays.
- Read the ingredients if you have reacted before, and look for PPD.
- Buy from a trusted source: all Care Outlet products are original and come from the brands' official agents inside and outside Saudi Arabia.
Common mistakes
- Skipping the allergy test because the dye worked before.
- Leaving dye on longer thinking it will last longer.
- Going from black to light blonde in one home session.
- Dyeing eyebrows or eyelashes with hair dye.
- Dyeing without gloves or on an irritated or broken scalp.
Frequently asked questions
How many hours before dyeing should I do the allergy test?
Do it at least 48 hours before, as the NHS advises, following the method on the pack. Repeat it before every dye job, even with a product you have used before, because sensitivity can develop with repeated exposure. If you see redness, itching or swelling, do not use the dye.
Is ammonia-free hair dye safe?
Ammonia-free usually means a milder smell, but it does not mean the dye cannot cause an allergy; it may still contain PPD. Many of these dyes are permanent, such as L'Oréal Oil 6.0 and Garnier Olia, so do the 48-hour allergy test and follow the instructions as with any dye.
What is the best brown hair dye?
The one closest to your natural color. For dark brown, Garnier Color Naturals 3 or Garnier Olia 4.0; for light brown, Garnier Olia 5.0; for powder fans, Bigen Dark Brown. Choose a natural (0) tone if gray coverage is your goal, and try the dye on a strand first.
What does a shade number like 7.1 mean?
7 is the level, meaning blonde, and 1 after the dot is an ash tone that cools warmth, as in L'Oréal Excellence Creme 7.1 Ash Blonde. The lower the first number, the darker the color: 1 is black and 10 is very light blonde.
How often can I dye my hair?
Touching up only the roots when they show is better than re-dyeing all your hair each time, because repeated dye on the ends dries them out. Space sessions out and use a root spray in between if needed.
What should I do if my scalp itches after dyeing?
Wash your hair and scalp with a mild shampoo straight away and stop using that dye. For mild symptoms, ask a pharmacist; if they persist or worsen, see a doctor. Swelling of the lips, tongue or throat, or difficulty breathing, is an emergency: call an ambulance immediately.
Where to buy original hair dye
The hair dyes section at Care Outlet offers shades from L'Oréal, Garnier, Wella and Bigen, online or at our branches across Saudi Arabia. For aftercare, browse shampoo and conditioner and hair oils and masks.
