1. THE COLOUR THEORY
Colourists use a simple equation to predict the finished look of every colour transformation; Hair’s starting point + colour chosen = end result.
2. THE LIGHTENING CURVE
For example, if you’re naturally a deep brunette 3/ but you want to add a few subtle highlights, lifting ribbons of hair to a 6/ will alter and brighten the underlying pigment, creating the perfect base for a deep caramel toner. Meanwhile, if you’re naturally a golden level 8/ but you’re craving a platinum ‘do, you’d need to be lifted to a very pale yellow 10/, before a toner is applied to counteract the yellow. That brings us to the next step…
3. THE COLOUR CIRCLE
For example, if blonde hair is yellow and warm but you want it to be icy and cool, you’d look to see which colour is opposite yellow on the Colour Circle. In this case, it’s purple. Then, a little bit of violet would be added to the hair formula to counteract the yellow tones. Only a dash is needed to subtly colour correct.
4. THE NUMBERING SYSTEM
You’ve got the full lowdown on the Lightening Curve and the Colour Circle. Now, let’s look at how they correlate with a numbering system to create a hair colour formula. Wella has its own universal numbering system, which means it’s the same across all colour products, whether hair is being treated to the pure permanent pigment of Koleston Perfect, or our kind-to-hair demi-permanent, Color Touch.
Every number in the numbering system is divided by a stroke. The figure before the stroke denotes the depth (how light or dark the hair is), and the figure after indicates what colour you’ll see. When you get your hair coloured, you might hear your colourist reeling off all manner of random numbers. The tables below show what each one means, and how they combine to make the most flawless hue.
The images above showing the depth numbering system on the left, and on the right, you’ll see the tone numbering system, as well as how depth and tone translate into a shade number.
Case in point? Say you’re going for a deep mahogany hair hue like in the photos below. To achieve it, you’ll want to reach the depth of a 4/, 5/ or a 6/ then add the tone of a red-violet /5 to achieve that rich, radiant finish, depending on the undertones.