Explain the process of "single process" hair coloring.

In the context of hair coloring, the process referred to as "single process" involves applying color in one step to either lighten or darken the hair. This method is designed to produce a uniform result, effectively altering the hair's natural color by adding pigments or lightening it through a chemical process.

The key feature of single-process coloring is its straightforward approach, which contrasts with more complex techniques that require multiple applications or interventions. By applying color in one step, a cosmetologist can achieve the desired shade without needing to blend or use additional products, such as bleach and toner, in separate stages. This makes single process coloring efficient and ideal for clients who seek a simple, all-over color change rather than highlights or multidimensional effects.

This process suits various situations, from covering gray hair to enhancing a person's natural hair color. It’s essential for cosmetologists to understand this method as it serves as a foundational technique in hair coloring, allowing for immediate transformation with minimal complexity.