Demi Hair Arias Line
DEMI Hair Assalt Arias Deep Natural Line is a professional-grade hair color series designed for precise depth control and natural-looking results. Each shade is formulated with a specific depth level (D-4 through D-9) and base tone - Warm Brown (WB), Cool Brown (CB), or Blue Brown (BB) - letting colorists dial in the exact warmth or coolness a client needs. The line is part of DEMI's Assalt permanent color system, widely trusted in Japanese salons for reliable gray coverage and consistent lift. With 10+ shades in stock, this collection covers everything from light brown to darkest natural.
By Skinsli editorial Updated
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Buying guide
DEMI Hair Assalt Arias Deep Natural Line: Shade & Application Guide
The DEMI Assalt Arias Deep Natural Line is a permanent oxidative hair color series from Japan built around a straightforward code system. Once you understand how depth levels and base tones interact, selecting the right shade for any client becomes predictable. This guide covers the naming convention, the three base families, mixing ratios, and what to expect from the color on natural versus pre-lightened hair.
How to Read the DEMI Shade Code
Every shade in this line follows the pattern D-[number] / [base]. The D stands for Deep Natural within the Assalt series. The number is the depth level - D-4 is the darkest available in this line, while D-9 sits at a lighter medium-brown range. The two-letter suffix (WB, CB, or BB) identifies the underlying tone family, which controls how the color reads in different lighting conditions.
Depth Levels D-4 Through D-9
D-4 delivers a very dark brown result, suitable for clients who want maximum depth or near-black coverage. D-5 steps up to a dark brown, D-7 and D-8 fall in the medium-brown range with noticeably different warm or cool overtones depending on base selection, and D-9 produces a lighter brown that works well on fine or already-lightened hair. Choosing the right depth number depends on the client's starting level and the target result - lifting beyond two levels is not recommended without a pre-lightening step.
Warm Brown (WB) Base
WB shades carry red-gold pigment that reads as toasty or chestnut in natural light. This base is the most forgiving on clients with naturally warm undertones and is a reliable choice when the goal is to add vibrancy and shine rather than neutralize existing warmth. In the Arias Deep Natural collection, WB is the most broadly stocked base - available from D-4 through D-9 - making it the go-to starting point for everyday brown services.
Cool Brown (CB) Base
CB shades use ash and violet pigment to cancel warmth. They work especially well on clients whose natural hair has orange or brassy tones from previous lightening, or who simply prefer a muted, contemporary brown with minimal warmth. CB tends to fade slightly faster than WB on porous hair, so a color-safe shampoo and periodic toning gloss are advisable for maintenance.
Blue Brown (BB) Base
BB shades sit between CB and a fashion tone - the blue pigment creates a deeper, more dimensional neutralization than ash alone and can produce a slate-brown finish at darker depths or a cool espresso at lighter ones. BB is particularly effective for gray blending on resistant white hair, where the blue pigment helps knock out the yellowish cast that often appears with standard ash formulas. The result reads as sophisticated and low-maintenance between appointments.
Developer Ratios and Processing Time
DEMI Assalt color is designed to be mixed 1:1 with the corresponding Assalt developer (3%, 6%, or 9% depending on the target lift). For the Deep Natural Line, a 6% (20 vol) developer is standard for one level of lift and solid gray coverage at natural base levels D-4 through D-7. D-8 and D-9 applications targeting more lift typically use 9% (30 vol). Processing time is 35 minutes at room temperature; heat acceleration is not recommended as it can shift the undertone.
Gray Coverage Performance
The Arias Deep Natural Line is formulated for at least 100% gray coverage when used at the correct developer strength and processing time. Resistant gray (often found at the temples and crown) benefits from the BB base, which provides extra neutralization without pulling blue on pigmented sections. For clients with more than 50% gray throughout, a 1:1 application directly on dry hair - rather than a root-to-tip wet application - gives more predictable coverage density.
When to Strand Test
A strand test is strongly recommended when switching from a different brand's formula, when the client has had chemical relaxing or perming within the past eight weeks, or when targeting D-9 on hair that is already at level 7 or lighter. The Deep Natural formula contains a higher concentration of direct dyes than typical fashion lines, and on very porous hair this can push the result darker than the target depth by half a level.
Post-Color Aftercare
DEMI recommends a pH-balancing rinse immediately after removal to close the cuticle and lock in the tone. At home, clients should use a sulfate-free, color-safe shampoo and avoid washing with hot water for the first 48 hours. BB and CB shades benefit from a violet-based conditioner used once a week to counteract any warm shift during the fade cycle. With proper aftercare, the Arias Deep Natural color maintains its tone for four to six weeks before a gloss refresh or root touch-up is needed.
FAQ
Frequently asked questions
FAQ
Frequently asked questions
What does 'Arias Deep Natural' mean in the DEMI Assalt system?
'Assalt' is DEMI's permanent oxidative color family, and 'Arias Deep Natural' is a sub-line within it focused on natural-looking brown tones with deep pigment saturation. The 'Deep Natural' descriptor signals that the shades are tuned for realistic, dimension-rich results rather than fashion or vivid colors.
What is the practical difference between WB, CB, and BB bases in the Arias line?
WB (Warm Brown) adds red-gold warmth and suits clients with neutral or warm natural undertones. CB (Cool Brown) uses ash pigment to neutralize existing brassiness and reads as a muted, modern brown. BB (Blue Brown) goes further - the blue pigment produces a deeper neutralization and a slightly slate-toned result, particularly effective on white or resistant gray hair.
What do the depth numbers D-4, D-5, D-7, D-8, and D-9 indicate?
The number represents the target depth level on the international hair color scale where 1 is black and 10 is lightest blonde. D-4 is a very dark brown, D-5 is dark brown, D-7 and D-8 are medium browns, and D-9 is a lighter medium brown. The depth you choose should match or be within two levels of the client's natural base to avoid unpredictable results.
Which developer percentage should I use with the DEMI Arias Deep Natural shades?
Mix 1:1 with DEMI Assalt developer. Use 3% (10 vol) for tone-on-tone or darkening with no lift. Use 6% (20 vol) for one level of lift and standard gray coverage - this is the most common choice for D-4 through D-7. Use 9% (30 vol) for D-8 and D-9 when a second level of lift is needed. Do not exceed 9% with this line.
Is the Arias Deep Natural Line suitable for clients with 100% white hair?
Yes. The formula provides full gray coverage when processed correctly (35 minutes, room temperature, 6% or 9% developer). For highly resistant white hair, the BB base provides extra pigment neutralization and is often the most reliable choice at D-5 or D-7 depth. Apply on dry hair for denser coverage on resistant sections.
How many Arias Deep Natural shades are currently available on skinsli?
There are 10+ shades in stock across the D-4 through D-9 depth range and WB, CB, and BB base families. The full availability is shown in the product grid above and reflects current inventory.
Why is the BB base recommended for gray blending rather than the CB base?
White hair lacks underlying warm pigment, so ash (CB) formulas can sometimes produce an unintended lavender or green cast on bright white sections. Blue pigment (BB) is more versatile on white - it neutralizes yellow without risking an overtly ashy result on the pigmented sections surrounding the gray. The BB base reads as a rich, dimensional brown rather than a flat ash.
Can the Arias Deep Natural shades be applied on previously bleached or highlighted hair?
Yes, with caution. On pre-lightened hair, the direct dye content in Deep Natural shades deposits more intensely and the result can land darker than the target depth. A strand test is essential. Use a 3% or 6% developer (never 9%) on bleached sections, and expect the color to fade faster due to higher porosity. A gloss treatment three to four weeks after application helps maintain tone.
What is the recommended processing time and can heat be used to speed it up?
Processing time is 35 minutes at room temperature. DEMI does not recommend heat acceleration for the Arias Deep Natural Line - elevated temperature can shift the undertone, particularly in BB shades where the blue pigment becomes more dominant. Covering with a processing cap (no heat) is acceptable to prevent oxidation from air exposure.
How long does the Arias Deep Natural color typically last before fading?
With sulfate-free shampoo and cold-water washing, the tone holds well for four to six weeks. WB shades tend to last slightly longer than CB or BB at the same depth, because warm pigments are larger in molecular size and resist fading better. A root touch-up or glossing service is typically scheduled at four to six weeks.
Is DEMI a professional Japanese salon brand?
Yes. DEMI Cosmetics is a Japanese professional haircare manufacturer with decades of distribution through licensed salons in Japan. The Assalt color line is formulated according to Japanese quality standards and is primarily sold through professional channels. skinsli imports authentic DEMI products directly.
How does the Arias Deep Natural Line differ from other DEMI Assalt color lines?
The Arias Deep Natural sub-line is specifically engineered for natural brown tones with enhanced gray coverage and depth. Other Assalt sub-lines (such as fashion or vivid series) prioritize vibrancy or unconventional tones at the expense of gray coverage performance. If the client's goal is a believable natural brown with reliable gray blending, the Arias Deep Natural is the appropriate choice within the Assalt family.
What shampoo do you recommend after using an Arias Deep Natural shade?
Use a sulfate-free, color-safe shampoo. For CB and BB shades, a violet-pigmented shampoo or conditioner used once a week will extend the cool tone between appointments. Avoid clarifying shampoos, which strip the color rapidly. DEMI's own aftercare line is formulated to work with the Assalt system, but any professional color-safe range performs adequately.