What does the third letter or number indicate in hair color formulation?

The third letter or number in hair color formulation indeed identifies the secondary pigment concentration. In the context of hair color, formulations typically consist of a primary color and a secondary color, which are combined to achieve a specific shade. The secondary pigment is used to modify the tone of the primary color and can have a significant impact on the overall result.

Understanding the concentration of this secondary pigment is critical for achieving the desired shade and ensuring that it complements the client's natural hair color and skin tone. This combination allows for a range of shades and effects, from ash tones to warmer colors, which are made possible by adjusting the levels of these pigments.

While other components such as the intensity of the primary color, the level of darkness, and the natural undertone play important roles in hair color formulation, the specific focus of the third letter or number directly correlates with how pronounced or subtle the secondary pigment is in the mixture. This knowledge is essential for hair colorists to create customized and precise color applications for clients.