In the work of a brow artist or colorist, selecting the right dye is not a matter of intuition, but of precise calculation and understanding of color. The two key components here are the tone and undertone of the dye.

These are not just words from the manual — they determine the final result: whether the color will be harmonious, or turn out unexpectedly red, green, or simply settle into a muddy blotch.

What is tone in dye?

Tone is the primary characteristic of a color — that is, how dark or light it is. In dyes for brows, hair, or lashes, this corresponds to the Level of Depth (LOD).

For example:

• Levels 1–2 — deep black

• Levels 3–4 — dark brown

• Levels 5–6 — medium brunette

• Levels 7–8 — light brunette/dark blonde

• Levels 9–10 — blonde

It is the tone that forms the base of the color, upon which the undertone and color nuance "settle."

What is an undertone and why is it critically important?

The undertone is the hidden or secondary shade component of the dye, which begins to appear when applied to skin/hair/brows. It gives the color its “mood” — warm, cool, or neutral.

For example:

• Ash (gray) undertone — neutralizes warmth

• Golden — makes the color warm and soft

• Copper — adds brightness and a reddish hue

• Red — gives rich warmth

• Violet/blue — cools the tone, suppresses unwanted warm pigments

And here’s the key: the same tone with different undertones results in two completely different outcomes!

Why is it important to consider the undertone?

1. To avoid unwanted shades

If you ignore the undertone, you might get a warm reddish tone where you wanted a cool graphite.

2. For neutralization

Cool undertones (blue, violet) mute warm natural pigments. Warm undertones — on the contrary — enhance them.

3. To work with every type of appearance

Warm complexions look better with dyes that have golden or copper nuances; cool types — with ashy, graphite, or bluish tones.

How to determine the undertone of a dye?

Many dye brands use numerical or alphanumeric systems that help identify both the tone and the undertone. For example:

6.1 —

• 6 — level of depth (dark blonde)

• 1 — ash undertone (blue/gray)

5.43 —

• 5 — medium brunette

• 4 — copper

• 3 — gold

→ So, the undertone is warm, with a copper-golden hue.

If the dye doesn’t have a clear coding system — test it on cotton pads. The undertone will “reveal itself” when reacting with oxygen or skin.

“Clean” vs “Dirty” Shades in Dye: What’s the Difference?

• A **clean color** is a dye with one distinct, dominant undertone. For example: 6.1 — cool dark blonde, 4.0 — natural brunette. It's “clean” because it doesn’t contain mixed tones.

• A **dirty color** results from mixing several undertones or applying the dye over the wrong base (e.g., cool dye on a warm base without neutralization).

Examples:

• Dye with ash and copper pigments → on warm hair, it may turn green

• Dye with a violet undertone + red base → violet gets “lost,” and the result is a muddy tone

To avoid muddiness, it’s important to understand:

• The undertone of the natural base

• The undertone of the dye

• How they interact with each other

Working with Darkening: What to Consider?

Darkening involves layering pigment over a lighter shade. It’s especially important to consider:

1. **Depth of tone** — if it’s too low, the pigment will be weak, and the warm or coppery base may show through.

2. **Dye undertone** — choose ones that can cover natural warmth (e.g., with blue or violet tones).

3. **Base temperature** of hair or brows — don’t darken without analysis. A cool dye on a warm base without neutralization can result in green, gray, or muddy shades.

Practical Tips:

• Always analyze the natural base — not only by tone, but also by temperature (warm, cool, neutral).

• Before using the dye — do a test on skin or a palette to see the true undertone.

• When creating mixes — don’t blend opposite undertones unless you clearly aim to neutralize.

• Learn to “read” the dye — not just by the packaging, but also by its reaction to oxygen and its interaction with skin.