L'Oréal Préférence 21 Blue Black Luminous, Fade-Defying Permanent Hair Colour for At-Home Use
For anyone who finds plain black too flat, 21 Blue Black adds a blue reflect that only shows in direct light. Indoors it reads as a deep black. In sunlight there is a cool shimmer running through it.
Permanent, so it covers rather than tints. Greys go to 100%, temples included, and the colour is formulated to resist fading for up to eight weeks. A conditioner comes in the box for the step after the rinse.
It behaves like any dark permanent going on, which means the mess is the main risk. Blue black stains skin and towels, so a barrier of balm along the hairline and an old towel round the shoulders are worth five seconds each.
- Deep blue black with a cool undertone in daylight
- 100% grey coverage from root to tip
- Up to 8 weeks before the tone starts to shift
- Enriched conditioner included in the kit
One thing to plan for. Blue black is a commitment, and getting out of it later takes more than a clarifying wash, so it suits people happy to stay dark for a while.
Colourant Gel: Aqua, Alcohol Denat., PEG-4 Rapeseedamide, Glyceryl Lauryl Ether, Laureth-5 Carboxylic Acid, Ethanolamine, Dipropylene Glycol, Hexylene Glycol, Ammonium Hydroxide, Toluene-2, 5-Diamine, Resorcinol, p-Aminophenol, m-Aminophenol, 2, 4-Diaminophenoxyethanol HCl, Ascorbic Acid, Polyquaternium-6, Parfum
- 24-hour delivery
- Every brand we carry ships within 24 hours, not just the hero lines. Order before 2pm and it leaves the same working day.
- Free over £40
- UK delivery is free on orders over £40. Below that it is a flat rate, shown at checkout before you pay.
- Tracking
- You get a tracking link by email the moment it is picked up.
- 30 days
- Send anything unopened back within 30 days for a full refund. No explanation needed.
- Opened it and it is wrong for your hair?
- Tell us what happened. Curl products are hard to judge from a photo, and we would rather swap it than have you stuck with it.
- We price match
- Find it cheaper somewhere else and we will match the price.
Application tips
Protect the hairline before you mix anything, because blue-black marks skin fast. The allergy alert test in the leaflet comes first.
Apply to dry hair, part into four, and work the roots first if this is your natural base, or the roots alone if you are keeping the length. Rinse for longer than feels necessary, until the run-off loses its blue cast, then condition.
Results
The shade sits deep and dark with a blue cast that shows when light hits it, which is what separates it from a plain black.
Greys disappear under it cleanly. The surface reads glossy rather than dull, so the colour looks rich and intentional, and it stays that way for weeks instead of washing down into a flat charcoal.
Composition
Full ingredients list
Colourant Gel: Aqua, Alcohol Denat., PEG-4 Rapeseedamide, Glyceryl Lauryl Ether, Laureth-5 Carboxylic Acid, Ethanolamine, Dipropylene Glycol, Hexylene Glycol, Ammonium Hydroxide, Toluene-2, 5-Diamine, Resorcinol, p-Aminophenol, m-Aminophenol, 2, 4-Diaminophenoxyethanol HCl, Ascorbic Acid, Polyquaternium-6, Parfum
Reviews
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