You want that rich blue-black shade on your dark hair without the hassle of bleaching. The problem is that most blue dyes barely show up on brown or black hair, leaving you with a colour that looks identical to what you started with. You need a dye that actually delivers visible blue tones on dark hair straight from the bottle.
This guide covers 13 blue-black hair dyes that work on dark hair in the UK. You’ll find permanent options for long-term commitment, semi-permanent formulas for experimenting, and everything in between. Each pick includes details on how the shade looks on dark hair, what the formula does for hair health, how long it lasts, and where to buy it from UK retailers like Amazon, Boots, and Superdrug. We’ve also included practical sections on choosing the right type of dye, prepping and applying at home, and keeping your blue-black colour vibrant for as long as possible.
How to choose a blue-black hair dye
Your hair colour, lifestyle, and commitment level determine which blue-black dye works best for you. Dark hair requires specific formulations that deposit enough pigment to create visible blue tones without bleaching. The right choice depends on whether you want a subtle tint or a bold statement shade.
Permanent vs semi-permanent formulas
Permanent dyes alter your hair structure and last until new growth appears. These formulas contain ammonia or similar alkaline agents that open the hair cuticle and deposit colour deep inside the cortex. You’ll see consistent blue-black tones for eight weeks or longer, making permanent options ideal if you want low maintenance and full grey coverage. The trade-off is that you’re committing to the colour until it grows out, and the process causes more hair damage than gentler alternatives.
Semi-permanent dyes sit on the hair’s surface without penetrating the cortex. These formulas fade gradually over 4 to 28 washes depending on the brand and your hair’s porosity. They work brilliantly for testing out blue-black before committing or refreshing faded permanent colour. Semi-permanent options contain no ammonia or peroxide, which means less damage but also means they won’t lighten your base colour or cover grey hair effectively.
If you have brown hair rather than black, permanent dyes usually give more visible blue tones because they can slightly lighten your base colour whilst depositing blue pigment.
Ingredients that protect or damage
Plex technology rebuilds broken bonds in your hair structure during the colouring process. Look for dyes that specifically mention plex, smart bond, or bond-building ingredients on the packaging. These formulations leave your hair stronger and shinier than standard dyes, particularly important if you colour frequently or use heat styling tools.
Avoid dyes with PPD (p-phenylenediamine), ammonia, and resorcinol if you have sensitive skin or a history of allergic reactions. Many UK brands now offer formulations free from these harsh chemicals without sacrificing colour intensity. Conditioning agents like argan oil, shea butter, and jojoba oil help counteract drying effects, though they can’t fully prevent damage from permanent dyes.
Matching intensity to your starting shade
Black hair takes blue-black dye differently than brown hair. On jet-black hair, you’ll see a subtle blue sheen that’s most visible in direct sunlight or bright indoor lighting. Brown hair ranging from light to dark brown shows more obvious blue tones because the lighter base allows more colour to show through. Very dark brown hair (level 3 or darker) gives results similar to black hair with a gentle blue tint rather than vibrant colour.
Check the colour chart on the dye packaging for realistic expectations. Most brands photograph their results on different starting shades, showing you exactly what to expect on hair similar to yours. Ignore marketing photos of bright blue hair unless they specifically state the model’s hair was pre-lightened or bleached.
Budget and UK availability
Drugstore brands from Boots and Superdrug cost £5 to £10 per box and work well for most people. These options include L’Oréal, Schwarzkopf, Garnier, and Superdrug’s own range. Professional or speciality brands range from £10 to £20 and often include better conditioning treatments or plex technology. Amazon stocks both categories with next-day delivery, making it convenient if your local shops don’t carry the specific shade you want.
Buy two boxes if your hair reaches past your shoulders. One box rarely covers long or thick hair completely, and you don’t want to run out halfway through application.
How to prep and apply at home
Proper preparation prevents patchy results and messy disasters when you colour your hair at home. Blue-black dyes show every mistake on dark hair, so taking time to prep correctly makes the difference between salon-quality results and an uneven finish. You’ll need about two hours from start to finish, including processing time, so choose a day when you’re not rushed.
Patch test and strand test first
Run a patch test 48 hours before colouring by applying a small amount of mixed dye to the inside of your elbow. Leave it for the recommended time, rinse, and watch for redness, itching, or swelling. Even if you’ve used hair dye before, formulations change and allergic reactions can develop at any time. Skip this step and you risk a severe allergic reaction across your entire scalp.
Test a hidden strand of hair to preview the exact shade you’ll get. Mix a tiny amount of dye, apply it to a small section underneath your hair near the nape, and process for the full recommended time. This shows you whether the blue tones will be visible enough on your specific hair colour and saves you from disappointment after dyeing your whole head.
Gather your supplies and protect your space
Collect everything before you start mixing the dye because most formulas begin working immediately after you combine the components. You need the dye kit, an old t-shirt you don’t mind staining, petroleum jelly or thick moisturiser, plastic gloves (extras if the kit only includes one pair), a timer, hair clips for sectioning, and an old towel for your shoulders. Place newspaper or an old shower curtain on your bathroom floor because blue-black dye stains grout and linoleum permanently.
Apply petroleum jelly along your hairline, ears, and neck before you start. This barrier prevents dye from staining your skin, which can take days to fade. Wear the old t-shirt rather than wrapping a towel around yourself because dye seeps through towels onto whatever you’re wearing underneath.
Section and apply systematically
Divide your hair into four equal sections using clips: split it down the middle from forehead to nape, then split each side horizontally from ear to ear. This systematic approach prevents you from missing patches, especially at the back where you can’t see easily. Start at the roots in the back sections because they need the most processing time and receive the least heat from your scalp.
Work in half-inch subsections within each quarter, applying dye from roots to ends. Saturate each piece thoroughly rather than skimming over it lightly. When you’ve covered all sections, use your gloved fingers to massage the dye through your hair, ensuring every strand gets coated. The best blue black hair dye uk options work better with generous application rather than sparse coverage.
Set a timer for the exact processing time stated on the packet because leaving dye on longer doesn’t make the colour more intense on unbleached dark hair.
Rinse with lukewarm water until it runs clear, then apply the included conditioner if your kit contains one. Skip shampoo on the first wash because it strips some of the deposited pigment before it fully sets.
Aftercare tips for dark blue-black hair
Blue-black hair fades faster than standard black dye because the blue pigment molecules are larger and wash out more easily. Your aftercare routine directly impacts how long the colour lasts and how vibrant it stays between applications. Even the best blue black hair dye uk formulas need proper maintenance to keep that rich blue sheen looking fresh rather than muddy or brassy.
Washing technique and water temperature
Wash your hair in cool or lukewarm water rather than hot because heat opens the hair cuticle and releases pigment with every wash. Cold water seals the cuticle and locks colour inside, which can extend your blue-black shade by several weeks. You’ll feel the temperature difference, but your colour will thank you for it.
Reduce washing frequency to twice a week or less if your hair type allows it. Each wash strips some pigment, so spacing out your shampoo sessions keeps the blue tones visible longer. Use dry shampoo between washes to absorb oil at the roots without touching the colour. When you do wash, focus shampoo on your scalp only and let the runoff clean the lengths rather than scrubbing dye out of every strand.
Products that preserve blue tones
Choose sulphate-free shampoo and conditioner formulated for colour-treated hair because sulphates are harsh detergents that strip pigment aggressively. Look for bottles that specifically state "colour safe" or "colour protect" on the label. These gentler formulas clean your hair without destroying the blue pigment you worked hard to deposit.
Apply a blue or purple toning conditioner once weekly to refresh the blue-black shade between dye applications. These deposit a small amount of pigment that counteracts any fading or warmth that develops over time. Leave it on for three to five minutes during your shower, then rinse thoroughly.
Deep condition weekly with a hydrating hair mask to repair damage and smooth the cuticle, which helps reflect light and makes your colour look richer.
Heat styling and UV protection
Limit heat styling tools or use them on the lowest effective temperature setting because high heat fades blue pigment rapidly. Apply a heat protectant spray before using straighteners, curling irons, or blow dryers. The barrier created by these products reduces colour loss whilst protecting your hair from heat damage.
Wear a hat in strong sunlight or apply a UV protection spray designed for hair because sun exposure bleaches blue tones into muddy greenish-brown shades. This matters most during summer months or holidays in sunny locations. UV filters work similarly to sunscreen on your skin by blocking the rays that break down colour molecules.
1. Smart Beauty Sapphire Black hair dye
Smart Beauty’s Sapphire Black delivers professional blue-black results with added plex technology that rebuilds hair bonds during colouring. This UK-made permanent dye contains no PPD, ammonia, or resorcinol, making it suitable for sensitive scalps whilst still providing rich pigment deposit on dark hair. The formula combines vegan ingredients with bond-building science for colour that doesn’t compromise hair health.
Shade and coverage on dark hair
Sapphire Black creates a deep black base with visible blue shimmer on both brown and black hair. You’ll see the blue tones most clearly in natural daylight and bright indoor lighting, where the sapphire reflects catch the light. On jet-black hair, the result appears as a subtle blue sheen, whilst dark brown hair (levels 3 to 4) shows more obvious blue tones throughout. The coverage extends to 100% grey hair, making this one of the best blue black hair dye uk options for anyone dealing with silver strands alongside their colour goals.
Formula and hair health benefits
Plex technology actively repairs broken bonds in your hair structure as the colour processes, leaving strands stronger than before you dyed. The formula deposits pigment whilst rebuilding the internal structure damaged by previous colouring, heat styling, or chemical treatments. You’ll notice improved shine and smoothness immediately after rinsing because the plex strengthens each strand from the inside out rather than just coating the surface.
Longevity and fade pattern
This permanent dye lasts eight weeks or longer with proper aftercare, fading gradually to a softer blue-black rather than turning brassy or muddy. The blue tones remain visible throughout the fade process, maintaining that sapphire quality even as the intensity decreases. Root regrowth becomes your main concern rather than colour loss on the lengths.
The plex formula means your hair stays healthier through multiple applications, so you can maintain the shade long-term without accumulating damage.
Best for and where to buy in the UK
This dye suits anyone with dark hair who wants visible blue-black colour with added hair care benefits. You’ll get the best results if you prioritise ethical products and want permanent colour that strengthens rather than weakens your hair. Purchase directly from smartbeautyshop.com for the full product range and expert guidance on shade selection.
2. L’Oréal Colorista permanent gel blue black
L’Oréal’s Colorista range brings bold colour to dark hair without bleaching, and the blue black shade delivers exactly what the name promises. This permanent gel formula spreads easily through your hair and processes in 20 minutes, making it one of the quickest options for achieving blue-black tones at home. The kit includes everything you need for application plus a deep conditioning mask to use after colouring.
Shade and coverage on dark hair
This dye creates a noticeable blue sheen on dark brown hair (levels 4 to 5) and a subtle blue tint on black hair. You’ll see the colour most clearly in daylight, where the blue reflects strongly against your base shade. The pigment deposit is generous enough to show up without pre-lightening, though the intensity depends on your starting shade. Dark brown hair takes the colour more vibrantly than jet black, giving you that rich blue-black depth that catches attention.
Formula and hair health benefits
The gel texture makes application straightforward because it stays where you put it rather than dripping down your neck. L’Oréal formulated this with pure dyes that deliver intense colour, and the included conditioning mask contains nourishing ingredients that smooth your hair after processing. You won’t find ammonia-free claims here because this is a permanent formula, but the mask helps counteract dryness.
Longevity and fade pattern
This permanent dye lasts up to eight weeks with proper care, fading gradually to a softer black rather than developing warm tones. The blue undertones stay visible throughout the fade, maintaining that cool-toned finish you applied it for. Root regrowth becomes visible around week four on dark hair.
The colour chart on the box shows realistic results for different starting shades, so check it before purchasing to confirm the outcome matches your expectations.
Best for and where to buy in the UK
This suits you if you want quick processing time and don’t mind a formula with ammonia for permanent results. Pick this among the best blue black hair dye uk options when you need reliable drugstore availability. Purchase from Amazon, Boots, or Tesco for prices around £8 to £10 per box.
3. Schwarzkopf Live Cosmic Blue 090
Schwarzkopf’s Live Intense Colour range targets medium brown to black hair with vibrant shades that deposit without bleaching. Cosmic Blue 090 combines black pigment with subtle blue undertones for a sophisticated finish rather than an obvious costume effect. This permanent vegan formula includes a vibrancy serum with vitamins and oils that condition your hair whilst the colour processes.
Shade and coverage on dark hair
This dye creates a very subtle blue tint on black hair that appears mainly in direct sunlight or bright indoor lighting. Your hair will look predominantly black with a cool-toned finish rather than showing obvious blue colour. Dark brown hair (level 3 to 4) takes slightly more visible blue tones, though you’ll still get a subdued effect compared to bolder blue-black options. The coverage extends to 100% grey hair, making this work for mature hair alongside younger clients wanting fashion colour.
Formula and hair health benefits
The vibrancy serum contains vitamins and oils that smooth your hair cuticle during processing, leaving strands shinier than before you applied the dye. This permanent formula uses standard hair colour chemistry, so you’ll get ammonia and peroxide in the mix. The conditioning elements help offset dryness that permanent dyes typically cause, though they can’t eliminate damage completely.
If you want blue-black that’s basically black with just a hint of cool tone, this delivers exactly that effect without going bold.
Longevity and fade pattern
This permanent colour lasts eight weeks or longer with proper aftercare, maintaining that subtle blue tint throughout the fade. You won’t see dramatic colour shifts because the blue component stays understated from start to finish.
Best for and where to buy in the UK
This suits you if you want the most subtle option among the best blue black hair dye uk choices, perfect for conservative workplaces or testing blue-black before committing to bolder formulas. Purchase from Amazon, Superdrug, or Boots for around £5 to £8 per box.
4. L’Oréal Casting Creme Gloss blue black
L’Oréal’s Casting Creme Gloss offers ammonia-free colouring in a semi-permanent formula that lasts longer than most temporary options. This 210 blue black shade contains royal jelly in its conditioning treatment, making it one of the gentler choices among the best blue black hair dye uk selections. The creme texture applies smoothly and rinses clean without lingering chemical smells that typically plague permanent dyes.
Shade and coverage on dark hair
This shade deposits a subtle blue-black tint on very dark brown and black hair, creating a cool-toned finish that reads as sophisticated rather than bold. You’ll see the blue most clearly in natural daylight, where your hair catches the light and reflects that gentle sapphire undertone. The colour shows more obviously on dark brown hair (level 3 to 4) than on jet black, though both achieve that coveted blue-black depth without looking artificial.
Formula and hair health benefits
The ammonia-free formula produces no harsh smell during application or processing, making this comfortable to use at home without ventilation concerns. Royal jelly in the conditioning treatment nourishes your hair after colouring, leaving it soft and manageable. You won’t get the same permanent intensity as ammonia-based dyes, but your hair suffers significantly less damage in exchange.
Longevity and fade pattern
This semi-permanent option lasts up to 28 washes, which bridges the gap between temporary colour and true permanent dye. The fade stays cool-toned throughout rather than developing warm or brassy notes. You’ll need to reapply more frequently than permanent options.
This longer-lasting semi-permanent formula gives you commitment without the permanent consequences, ideal if you want flexibility to change shades seasonally.
Best for and where to buy in the UK
This suits you if you want minimal damage and can commit to more frequent touch-ups. Pick this when you prefer no ammonia smell during application. Purchase from Amazon, Boots, or Superdrug for around £6 to £9 per box.
5. Clairol Nice’n Easy blue black
Clairol’s Nice’n Easy line delivers permanent colour with an oil-infused formula that conditions whilst it dyes. This blue black shade combines deep pigment with nourishing oils that leave your hair softer than standard permanent dyes, making it a gentler option for regular touch-ups. The creme formula spreads evenly and processes without harsh ammonia fumes.
Shade and coverage on dark hair
This shade creates a rich black base with subtle blue undertones that appear most clearly in natural light. You’ll see a sophisticated cool-toned finish rather than obvious blue colour, making this suitable for professional environments. Dark brown hair shows slightly more blue reflection than jet black, though both achieve that elegant blue-black depth without looking artificial.
Formula and hair health benefits
The oil-infused formula conditions your hair during the colouring process, reducing the dryness that typically follows permanent dye applications. You’ll get complete grey coverage without the scalp irritation that some permanent dyes cause. The creme texture makes application straightforward and mess-free compared to runny liquid formulas.
Longevity and fade pattern
This permanent option lasts eight weeks or longer with proper maintenance, fading gradually without developing warm or brassy tones. The blue undertones stay subtle throughout the colour’s lifespan.
This works brilliantly if you want permanent colour that feels gentler on your hair than standard box dyes.
Best for and where to buy in the UK
This suits you if you need reliable permanent coverage with added conditioning benefits among the best blue black hair dye uk choices. Find it at Boots and Amazon for around £6 to £9 per box.
6. Garnier Nutrisse Midnight Blue 3.10
Garnier’s Nutrisse Ultra Color range provides permanent blue-black tones for dark hair with a nourishing five-oils conditioner included in every kit. This 3.10 Midnight Blue shade deposits cool-toned pigment on unbleached brown and black hair, creating that coveted blue-black finish without pre-lightening. The formula targets medium brown to black hair specifically, making it one of the best blue black hair dye uk options for darker base colours.
Shade and coverage on dark hair
This shade creates a black-blue tint that leans more towards black than vibrant blue, giving you a sophisticated dark finish with subtle cool undertones. You’ll see the blue most clearly in direct sunlight, where your hair reflects that midnight quality. Dark brown hair (level 3 to 4) shows more obvious blue than jet black hair, though both achieve a cool-toned black finish rather than bold colour.
Formula and hair health benefits
The five-oils conditioner restores your hair during and after the colouring process, delivering up to three times more shine than untreated hair. This permanent formula contains nourishing oils that counteract dryness whilst the colour deposits. You’ll notice improved smoothness and gloss immediately after rinsing because the conditioner works alongside the dye rather than as an afterthought.
Longevity and fade pattern
This permanent colour lasts up to eight weeks with proper aftercare, maintaining its cool-toned black finish throughout the fade. The blue undertones stay subtle rather than shifting to warm or brassy notes.
Best for and where to buy in the UK
This suits you if you want black hair with just a hint of blue rather than obvious colour. Purchase from Amazon, Boots, or Superdrug for around £7 to £10 per box.
7. Garnier Color Sensation Vivids deep blue
Garnier’s Color Sensation Vivids line delivers bolder blue tones than standard blue-black dyes, making this deep blue shade stand out among the best blue black hair dye uk options for anyone wanting visible colour. This permanent formula contains mother of pearl and rose oil that condition your hair whilst depositing intense pigment on unbleached dark hair. The vivid range targets people who want statement colour without the commitment of maintaining bleached hair.
Shade and coverage on dark hair
This deep blue creates noticeably brighter results than subtle blue-black options, giving you a blue tone that reads clearly as blue rather than appearing as a tint. You’ll see strong colour in all lighting conditions, not just direct sunlight. Dark brown hair (levels 4 to 5) shows the most vibrant results, whilst black hair takes a rich blue-black finish with more obvious blue than gentler formulas deliver.
Formula and hair health benefits
Mother of pearl and rose oil condition your hair throughout the colouring process, leaving strands with mirror shine and smoothness. This permanent formula delivers that conditioning boost whilst depositing vivid pigment that stands out on dark hair.
Longevity and fade pattern
This permanent dye lasts eight weeks or longer with proper care, maintaining its vivid quality throughout. The colour fades gradually to softer blue tones rather than turning muddy.
Best for and where to buy in the UK
This suits you if you want obvious blue colour rather than subtle tints. Purchase from Amazon or Boots for around £7 to £10 per box.
8. Superdrug Vibrance Midnight Blue 2.8
Superdrug’s own-brand Vibrance range offers affordable permanent colouring for UK customers who want quality results without premium pricing. This Midnight Blue 2.8 shade contains jojoba oil and pro-vitamin B5 that protect and condition your hair during the colouring process, making it a budget-friendly choice among the best blue black hair dye uk selections. The formula delivers glossy results whilst keeping costs low for regular maintenance.
Shade and coverage on dark hair
This shade creates a blue-black finish on dark brown hair (level 3 to 4) with subtle blue undertones that appear most clearly in natural light. You’ll see a cool-toned black result rather than obvious blue colour, making this suitable for understated looks. Black hair takes the dye as a gentle blue tint that reads as sophisticated rather than bold.
Formula and hair health benefits
Jojoba oil and pro-vitamin B5 condition your hair whilst the colour processes, leaving strands more glossy and protected than standard permanent dyes deliver. This formula makes your colour more vibrant whilst defending against damage during application.
Longevity and fade pattern
This permanent colour lasts around six weeks before fading becomes noticeable, slightly shorter than premium brands but acceptable given the lower price point.
The fade stays cool-toned throughout rather than developing warm notes, maintaining that blue-black quality until you reapply.
Best for and where to buy in the UK
This suits you if budget matters without sacrificing decent results. Purchase exclusively from Superdrug stores or superdrug.com for around £4 to £6 per box.
9. Crazy Color blue-black semi permanent
Crazy Color’s blue-black delivers semi-permanent colouring without ammonia or peroxide, making it one of the gentlest options among the best blue black hair dye uk selections. This vegan and cruelty-free formula sits on your hair’s surface rather than penetrating deep inside, reducing damage whilst still depositing visible colour on dark hair.
Shade and coverage on dark hair
This shade creates a subtle blue-black tint on black hair that shows mainly in bright lighting conditions, giving you a cool-toned finish. Dark brown hair (level 3 to 4) takes more obvious blue tones because the lighter base allows pigment to show through clearly. You’ll see an intense blue-black sheen that catches light without looking artificial.
Formula and hair health benefits
This ammonia-free and peroxide-free formula causes minimal damage because it doesn’t alter your hair structure or natural pigment. Your hair stays healthier than with permanent options, maintaining its natural strength and elasticity. The gentle formula suits frequent reapplication without accumulating damage over time.
Longevity and fade pattern
This semi-permanent dye lasts 5 to 15 washes depending on your hair’s porosity and washing frequency. The colour fades gradually rather than disappearing suddenly, maintaining a cool-toned finish throughout.
Semi-permanent formulas work brilliantly for testing blue-black before committing to permanent colour.
Best for and where to buy in the UK
This suits you if you want minimal commitment and gentle formulas that protect hair health. Purchase from Amazon for around £4 to £7 per bottle.
10. Adore Royal Navy semi permanent
Adore’s Royal Navy delivers deep blue tones without harsh chemicals like peroxide, ammonia, or alcohol that dry out your hair. This semi-permanent formula works particularly well on dark hair because it deposits rich pigment that shows up clearly without requiring pre-lightening. The concentrated colour comes in a convenient bottle format that makes application straightforward for home use.
Shade and coverage on dark hair
This shade creates noticeable blue-black results on brown hair (levels 3 to 5), where the royal navy pigment shows through strongly. Your hair will look darker than its starting shade with obvious blue tones visible in all lighting conditions. Black hair takes the colour as a rich blue sheen that catches light beautifully without looking artificial.
Formula and hair health benefits
This gentle formula contains no ammonia, peroxide, or alcohol, protecting your hair from the damage that permanent dyes cause. Your strands stay strong and healthy whilst taking on intense colour. The lack of harsh chemicals makes this suitable for frequent reapplication without accumulating damage over time.
Longevity and fade pattern
This semi-permanent colour lasts 4 to 8 weeks depending on your washing frequency and hair porosity. The fade stays cool-toned throughout rather than shifting to warm notes.
Adore’s formula works brilliantly on dark hair without bleaching, making it one of the best blue black hair dye uk options for gentle colouring.
Best for and where to buy in the UK
This suits you if you want visible blue tones with minimal hair damage. Purchase from Amazon or FeelUnique for around £5 to £8 per bottle.
11. Manic Panic blue for dark hair
Manic Panic’s blue shades offer semi-permanent colouring with zero animal products or testing, making this a fully vegan and cruelty-free option among the best blue black hair dye uk selections. The High Voltage Classic Cream formula contains no PPD, ammonia, or harsh chemicals that damage hair structure. Shades like Rockabilly Blue and After Midnight work on dark hair when you want deeper blue-black tones rather than their signature bright colours.
Shade and coverage on dark hair
Darker Manic Panic shades create subtle blue tints on black hair and more visible blue tones on brown hair (levels 3 to 5). You’ll see the colour most clearly in natural daylight where the blue reflects against your base shade. After Midnight delivers the deepest blue-black results on unbleached dark hair, whilst Rockabilly Blue gives a slightly lighter finish.
Formula and hair health benefits
This conditioning cream formula contains no peroxide or ammonia, protecting your hair from chemical damage whilst depositing colour. Your strands stay healthy and strong because the dye sits on the surface rather than penetrating deep inside.
Longevity and fade pattern
This semi-permanent colour lasts 4 to 6 weeks depending on washing frequency. The fade stays cool-toned throughout rather than developing warm notes.
Rinse with cold water after applying to lock colour in and extend its lifespan.
Best for and where to buy in the UK
This suits you if vegan and cruelty-free products matter alongside visible blue tones. Purchase from Amazon for around £10 to £13 per jar.
12. Knight & Wilson Colour Freedom Truly Blue
Knight & Wilson’s Colour Freedom takes a colour conditioner approach that deposits pigment whilst treating your hair with shea butter and argan oil. This ultra-vibrant semi-permanent option washes out after ten shampoos, making it one of the safest ways to experiment with blue-black tones among the best blue black hair dye uk choices. The formula skips harsh chemicals like peroxide completely, giving you beginner-friendly colouring that feels more like a treatment than a dye session.
Shade and coverage on dark hair
This shade creates vibrant blue tones on dark brown hair (levels 3 to 5), where the colour shows through strongly enough to make a statement. You’ll see obvious blue rather than subtle tints, making this bolder than many blue-black options. Black hair takes a gentle blue sheen that appears mainly in bright lighting conditions.
Formula and hair health benefits
Shea butter and argan oil condition your hair during the colouring process, leaving strands softer and more manageable than before application. This colour conditioner contains no peroxide or harsh chemicals, protecting your hair from damage whilst depositing pigment.
Longevity and fade pattern
This semi-permanent colour lasts around ten washes, fading gradually to softer blue tones. The short lifespan suits experimenting with blue-black before committing to permanent formulas.
This works brilliantly for first-time colouring because the gentle formula and quick fade give you confidence without permanent consequences.
Best for and where to buy in the UK
This suits you if you want beginner-friendly colouring with strong conditioning benefits. Purchase from Amazon or Superdrug for around £6 to £9 per tube.
13. La Riche Directions Atlantic or midnight blue
La Riche Directions offers multiple blue shades that mix together for custom colour creation, making this one of the most versatile options among the best blue black hair dye uk selections. The Atlantic Blue and Midnight Blue shades work on dark hair when you want deeper tones rather than their brighter primary colours. This semi-permanent formula contains no ammonia or peroxide, giving you gentle colouring that protects your hair whilst depositing vivid pigment.
Shade and coverage on dark hair
Atlantic Blue creates a deeper blue-black finish on dark hair compared to their lighter shades, giving you noticeable colour on brown hair (levels 3 to 5). You’ll see strong blue tones in all lighting conditions rather than subtle hints. Black hair takes the colour as a rich blue sheen that appears most clearly in natural daylight, creating sophisticated depth without looking artificial.
Formula and hair health benefits
This ammonia-free and peroxide-free formula causes no structural damage to your hair because it sits on the surface rather than penetrating deep inside. Your strands stay healthy and strong whilst taking on intense colour. The ability to mix shades together lets you create your exact ideal blue-black tone by blending Atlantic Blue with darker shades.
Longevity and fade pattern
This semi-permanent colour lasts 4 to 8 weeks depending on your washing frequency and hair porosity. The fade stays cool-toned throughout rather than developing warm or brassy notes.
Mix multiple Directions shades to create your perfect custom blue-black that matches your vision exactly.
Best for and where to buy in the UK
This suits you if you want customisable colour with gentle formulas that protect hair health. Purchase from Amazon for around £4 to £6 per bottle.
Final thoughts
You now have 13 proven options for achieving blue-black hair on dark brown or black hair without bleaching. Each dye on this list delivers visible blue tones on unbleached hair, from subtle professional sheens to bolder statement shades that catch every light source. Your choice depends on whether you want permanent commitment, semi-permanent flexibility, or gentle conditioning formulas that protect your hair whilst adding colour.
Smart Beauty’s Sapphire Black stands out among the best blue black hair dye uk choices for combining plex technology with ethical vegan formulas that strengthen your hair during colouring. The bond-building science repairs damage whilst depositing rich sapphire tones. Browse the full Smart Beauty hair dye collection for blue-black options that prioritise both vibrant colour and hair health.
