What They Mean + How to Use Them

Let’s talk about hair color numbers and letters!

You know that feeling when you’re standing in the hair color aisle staring at a box that says something like “6NW” or “5RV” and you have absolutely no idea what any of it means?

I fielded this question all the time when I worked at Sally Beauty Supply.

Women would pick up a box, look at the label, put it back down, and walk away confused. And honestly, it doesn’t have to be that way. The hair color numbering system looks complicated but it’s actually pretty logical once someone breaks it down for you.

That’s exactly what this post does. By the end of it, you’ll be able to pick up any box of hair color and understand exactly what you’re looking at.

💡TIP: Save this article to your Hair Color board on Pinterest so you always have it handy when you need it! 👇🏼👇🏼👇🏼

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The Number: Your Hair Color Level

Let’s start with the hair color numbers.

The first thing you’ll see on a box of hair color is a number, and that number tells you one thing: how light or dark the color is.

Hair color levels are measured on a scale from 1 to 10. Level 1 is the darkest black, and level 10 is the lightest blonde. Every shade in between falls somewhere on that scale. The higher the number, the lighter the color.

Here’s a general guide to what each level looks like:

Hair Color Number Chart

Some color lines go up to level 11 or 12, which are high-lift blondes designed to lift the hair lighter than a standard level 10. You’ll usually see these labeled as “high-lift” on the box.

The hair color numbers tells you the depth of the color but nothing about its tone or warmth. That’s where the letters come in.

The Letter: Your Hair Color Tone

The letter (or letters) after the number tells you the base tone of the color. This is what determines whether the color is warm, cool, or neutral.

Here’s a breakdown of the most common hair color letters:

When a color has double letters like RV or NW, the first letter is always the dominant tone and the second is a supporting tone that adds depth or balance. So RV (red-violet) means the color is primarily red with violet woven through it.

How to Read a Full Hair Color Code

Now that you understand the level and the tone separately, let’s put them together.

5RV means a level 5 (light brown) with a red-violet tone. More red than violet.

8A means a level 8 (light blonde) with an ash tone. Cool and muted, no warmth.

6NW means a level 6 (dark blonde) with a neutral-warm tone. A natural, slightly warm shade without being overtly golden.

10G means a level 10 (lightest blonde) with a gold tone. Warm, bright, and luminous.

Once you know the formula, any combination of numbers and letters becomes readable.

The Professional Number System (Decimal System)

If you’ve ever looked at a professional hair color brand like Wella, L’Oréal Professionnel, or Redken, you may have noticed they use a slightly different system with decimal points instead of letters. For example: 6.3 or 5.1.

In this system, the number before the decimal is still the level (how light or dark). The number after the decimal is the primary tone, and if there’s a second number after that, it’s the secondary tone.

Here’s what the tone numbers mean in the professional system:

So 6.3 means a level 6 (dark blonde) with a gold tone. 5.1 means a level 5 (light brown) with an ash tone.

Some brands use a combination of both systems, with a level number plus letters.

For example, L’Oréal Professionnel might label a color as 6.13, which means level 6, with a primary ash tone (.1) and a secondary gold reflect (.3). It sounds complicated but once you see the pattern it becomes second nature.

Are Hair Color Numbers Universal?

The level system (1 to 10) is pretty consistent across most brands. If you’re a level 6 with one brand, you’ll generally be a level 6 with another.

The tone letters and numbers are where things vary. Every brand has its own system for coding tones and reflects. Clairol uses letters like N, W, and A. Wella uses decimal numbers. Redken uses a combination. Some brands create their own proprietary tone codes to differentiate themselves.

The practical takeaway is this: always check the shade name alongside the hair color numbers. Most brands give their colors descriptive names like “Light Ash Blonde” or “Medium Golden Brown” that tell you what the tone is regardless of the coding system they use. When in doubt, the name is your best guide.

💡TIP: You can always check with the manufacturer if you’re unsure.

How to Find Your Current Level

Before you can choose the right hair color, you need to know your starting level. Here’s how to figure it out.

Look at your natural roots in natural light, not bathroom light, which can distort the color. Compare what you see against a hair color level chart. Your roots are always your most accurate representation of your natural level because the lengths and ends may have been lightened or colored previously.

A few things to keep in mind when assessing your current level:

• Your natural level is the darkest part of your hair, usually at the roots and around the nape of your neck.
• The lengths and ends of your hair may be lighter due to sun exposure, heat styling, or previous color.
• Virgin hair, which is hair that has never been colored, is the most straightforward to assess because there’s no color history affecting the result.
• If you’re working with previously colored hair, your starting level and your natural level may be different, and that affects which developer you’ll need. You can read more about that in my guide to the different volumes of developer.

How to Choose the Right Hair Color Number

Once you know your current level and your target level, choosing the right hair color numbers becomes much more straightforward.

Going darker: Choose a color that’s 1-2 levels below your current level. Going darker is generally easier and more predictable than going lighter, and you can use a lower volume developer.

Staying at the same level: Look for a color at your current level with the tone you want. This is straightforward for adding a new tone without changing the depth.

Going lighter: This is where it gets more complicated. If you’re going 1-2 levels lighter on virgin hair, a permanent color with the right developer can work. If you’re going more than 2 levels lighter, or if your hair has been previously colored, you’ll likely need bleach first. Check out my guide to lifting hair color for the full breakdown.

Covering gray: Use a level that matches your natural base and choose an N (neutral) or W (warm) tone for the most natural-looking gray coverage. A cool or ash tone on gray can sometimes look flat or blue-toned, especially on coarser gray hair.

A Few More Things Worth Knowing

Some brands use double numbers before the tone to indicate extra intensity or gray coverage. For example, 33/02 or 55N means the color has an intensified base for stronger coverage on resistant gray hair.

If a color has the same tone letter repeated, like NN or RR, it means the tone is extra intense. NN means there’s double the neutral base, which makes it great for resistant gray. RR means the red is very vivid with no brown softening it.

The letter N on its own means neutral, which is a good middle-ground tone that works on most skin tones without pulling too warm or too cool.

When you see a W (warm) with hair color numbers, it means the color has warm golden undertones built in. This is often recommended for gray coverage because the warmth helps the color look natural and dimensional rather than flat.

FAQ

Final Thoughts

Once you understand how the level system works and what the tone letters mean, reading a hair color box becomes second nature. You really are learning a kind of shorthand that stylists use every day, and knowing it puts you in a much better position to choose a color that actually does what you want it to do.

The level tells you how light or dark. The letter tells you how warm or cool. Put them together and you have everything you need.

Until next time,

Your Turn: Did this help decode the hair color numbers for you? Drop your questions in the comments below!👇🏼👇🏼👇🏼

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