L'Oréal Professionnel Dia Light is an acidic, ammonia-free demi-permanent gloss colour — zero ammonia, zero lift, ultra conditioning. The reformulated NEW Dia Light is powered by a 1% Hyaluronic Acid complex that enrobes the hair fibre in a hydrating film for up to 82% glossier colour, instantly replenishes moisture and gives up to 3x less breakage after bleach (instrumental tests). It is an acidic-pH, vegan formula (no animal-derived ingredients) that deposits tone without lifting the base. This is the full Dia Light colour chart for professional use, with every shade by tonal family, how to read the codes, how to neutralise undertones, plus mixing, services and application.
How to read Dia Light shade codes
Dia Light uses a dual-coding system: a level (depth) followed by tone numbers, shown alongside an equivalent letter code. For example 5.32 / 5GV is a level 5 with a gold primary tone (.3 / G) and a violet secondary tone (.2 / V).
- Level runs from 1 (black) to 10 (lightest blonde) — the number before the dot.
- Tone is the number(s) after the dot, each with a letter code:
| Number | Letter | Tone |
|---|---|---|
| .0 | N | Natural |
| .1 | B | Blue (ash) |
| .2 | V | Violet |
| .3 | G | Gold |
| .4 | C | Copper |
| .5 | Rv | Red-Violet |
| .6 | R | Red |
| .7 | Gr | Green |
| .8 | M | Mocha |
Opposite tones on the colour wheel neutralise each other — so a blue/ash reflect (.1) knocks back orange, and violet (.2) cancels yellow.
Naturals
| Shade | Name |
|---|---|
| 9/9N | Very Light Blonde |
| 8/8N | Light Blonde |
| 7/7N | Blonde |
| 6/6N | Dark Blonde |
| 5/5N | Light Brown |
| 4/4N | Brown |
Blues & Greens (cool / ash)
| Shade | Name |
|---|---|
| 9.11/9BB | Iceberg Milkshake |
| 6.11/6BB | Charcoal |
| 9.1/9B | Icy Milkshake |
| 8.1/8B | Iced Latte |
| 6.1/6B | Cool Almond |
| 5.1/5B | Cool Smoked Walnut |
| 10.01/10NB | Soft Frosty Milkshake |
| 9.01/9NB | Frosty Milkshake |
| 7.01/7NB | Natural Frost |
| 5.07/5NGr | Sage |
| 10.18/10BM | Dazzling Pearl Milkshake |
| 9.18/9BM | Icy Pearl Milkshake |
| 8.18/8BM | Cool Pearl Milkshake |
Violets
| Shade | Name |
|---|---|
| 10.21/10VB | Pearl Sorbet Milkshake |
| 9.21/9VB | Sorbet Milkshake |
| 8.21/8VB | Icy Sorbet |
| 10.22/10VV | Iridescent Berry Milkshake |
| 9.2/9V | Iridescent Milkshake |
| 10.02/10NV | Soft Pearly Milkshake |
| 9.02/9NV | Pearly Milkshake |
Cool Browns & Blondes
| Shade | Name |
|---|---|
| 10.12/10BV | Frosty Pearl Milkshake |
| 9.12/9BV | Pearl Milkshake |
| 7.12/7BV | Cool Beige |
| 10.13/10BG | Vanilla Macaroon Milkshake |
| 9.13/9BG | Cool Buttercream |
| 7.13/7BG | Satin Blonde |
| 6.13/6BG | Walnut |
| 10.23/10VG | Pearly Gold Milkshake |
| 8.23/8VG | Lavender Honey |
| 6.23/6VG | Hazelnut Honey |
Mochas
| Shade | Name |
|---|---|
| 10.82/10MV | Pearly Glow Milkshake |
| 9.82/9MV | Iridescent Beige Milkshake |
| 7.8/7M | Mocha Latte |
Warm Browns & Blondes
| Shade | Name |
|---|---|
| 10.32/10GV | Sandy Milkshake |
| 9.31/9GB | Vanilla |
| 7.31/7GB | Almond |
| 5.31/5GB | Praline |
Golds
| Shade | Name |
|---|---|
| 9.03/9NG | Honey Milkshake |
| 9.3/9G | Light Gold |
| 8.3/8G | Light Brown Sugar |
| 7.3/7G | Brown Sugar |
| 6.3/6G | Gingerbread |
| 8.34/8GC | Light Caramel |
| 6.34/6GC | Honey Chestnut |
Coppers
| Shade | Name |
|---|---|
| 8.43/8CG | Copper Sunset |
| 7.43/7CG | Sunset (Rubilane™) |
| 7.40/7CCC | Firelight |
| 6.45/6CRv | Cinnamon |
| 6.46/6CR | Autumn (DM5 / Rubilane™) |
Reds
| Shade | Name |
|---|---|
| 6.64/6RC | Garnet (DM5 / Rubilane™) |
| 6.66/6RR | Red (DM5 / Rubilane™) |
| 5.66/5RR | Ruby (DM5 / Rubilane™) |
Clear
The Clear shade adds shine and transparency with no colour deposit. Use it to modulate any Dia Light shade: add no Clear to maximise colour deposit and toning power, or blend in roughly 1/4, 1/2 or 3/4 Clear to increase transparency for a softer, sheerer result.
Note: DM5 and Rubilane™ shades (such as Sunset, Autumn, Garnet, Red and Ruby) must be used on their own and not combined with other shades.
Choosing a shade to neutralise an undertone
Dia Light is built around colour theory: choose the reflect opposite the unwanted undertone to cancel it, and decide how strongly to neutralise. Working from the most corrective to the warmest:
- Very neutralising (strongest cancel of warmth): .11, .12, .21, .22 — cool blue and violet reflects for yellow, orange and red undertones after lightening.
- Neutralising: .1, .01, .02, .2, .07 — balanced cool/ash and violet reflects to refine without going too cool.
- Softening: N, .13, .23, .8 — natural and soft beige/mocha reflects that gently soften warmth and add depth.
- Warming: .03, .3, .31, .32, .34, .40, .43, .45, .46, .64, .66 — gold, copper and red reflects that add or enhance warmth rather than cancel it.
As a rule, the lighter and warmer the undercoat (yellow to pale yellow after lift), the cooler the reflect you need to neutralise it.
The Milkshake shades
The Milkshake shades are the high-level (8–10) pearly, cool and beige-iridescent toners, designed for dimensional, luminous, pearly results on pre-lightened hair. Cool pearls such as 10.18 Dazzling Pearl, 9.18 Icy Pearl and 8.18 Cool Pearl neutralise warmth, while beige-iridescent shades like 10.82 Pearly Glow and 9.82 Iridescent Beige enhance natural undertones.
Mixing and developer
Mix Dia Light 1:1.5 with Diactivateur — 60ml (one tube) of Dia Light to 90ml of Diactivateur. Keep the 1:1.5 ratio if you scale the quantities up. Use a non-metallic bowl or applicator bottle, and if you use a bottle, open it straight after mixing to release pressure. The NEW Dia Light is designed to be used with 6 or 9 volume Diactivateur.
Choosing your Diactivateur strength:
- 6 vol (1.8%): subtle reflect, ideal for tone-on-tone colour.
- 9 vol (2.7%): a balanced reveal of reflection and depth; can darken by up to around 2 levels.
- 15 vol (4.5%): maximum intensity and reveal of reflection — referenced in some advanced L'Oreal glossing and post-lightening techniques; always follow the instructions on your current tube and carton.
For faster all-over bottle work you can add Dia Light Liquifier to the mix to boost fluidity and transparency (it is not a developer).
Application
On dry hair, apply with a bottle or brush and develop for 20 minutes. For a toning service, apply to shampooed, towel-dried hair and develop for 5–20 minutes depending on the result. Then emulsify gently, rinse thoroughly and shampoo with Metal Detox or Vitamino Color Spectrum. Full ratios across the L'Oreal range are in our mixing guide.
Dia Light glossing services
Beyond simple toning, Dia Light powers two popular salon glossing services:
- Gloss after lightening: following a Blond Studio lightening service, apply a Dia Light shade (modulated with Clear) to neutralise the warm undercoat and add an ultra-glossy finish, with no impact on the natural base.
- Gloss as a grey-coverage take-through: during a permanent root service with Majirel or INOA, take a Dia Light shade (2–3 levels lighter than the base) through the mid-lengths and ends to revive radiance and refresh tone without over-sensitising or overloading colour, then rinse both formulas together.
When to use Dia Light
- Toning and glossing pre-lightened hair, balayage and foils
- Refreshing faded mid-lengths and ends without heavy root build-up
- Tone-on-tone colour and blending up to around 50% grey
- Adding shine and correcting tone between permanent colour services
Shop Dia Light at Hairco and Beauty
We supply the full Dia Light range and Diactivateur to salons at trade prices, with fast UK delivery. Browse our semi-permanent & demi colour and developers, or read the complete Dia Light colourist's guide.
Dia Light FAQs
What developer do you use with Dia Light?
Dia Light is used with L'Oréal Diactivateur at 6 volume (1.8%) or 9 volume (2.7%), mixed 1:1.5 — 60ml of Dia Light to 90ml of Diactivateur.
What is the Dia Light mixing ratio?
The mixing ratio is 1:1.5 — one 60ml tube of Dia Light to 90ml of Diactivateur.
Does Dia Light cover grey?
Dia Light blends grey tone-on-tone up to around 50%. For full white coverage, use a permanent colour such as Majirel or INOA.
Is Dia Light ammonia-free?
Yes. Dia Light is an acidic, ammonia-free demi-permanent gloss colour, and the NEW formula is powered by a 1% Hyaluronic Acid complex for up to 82% glossier colour.
How long do you leave Dia Light on?
Develop for 20 minutes on dry hair, or 5–20 minutes for a toning application on shampooed, towel-dried hair.
Written by Charlotte Read, Content Writer at Hairco & Beauty. Charlotte has over six years' experience in professional hair and beauty, and our guides are informed by colleagues with 100+ years of combined salon experience and by insight from the trade customers we supply. More about our content.
