Which approach combines two methods into one process to achieve the desired hair color?

The approach that combines two methods into one process to achieve the desired hair color is a double process. In hair coloring, a double process typically involves first lightening the hair and then depositing color in a single appointment. This is particularly useful for achieving significant color changes, such as going from dark to light or when a vibrant fashion color is desired on previously colored hair.

A double process allows for a more uniform and vivid application of color since it prepares the hair by lifting it to the desired level of lightness before adding the new hue. This method is especially advantageous because it can create a more dynamic and multi-dimensional result, ensuring that the final color appears fresh and well-blended.

Understanding the double process is crucial for colorists, as it allows them to correctly assess the needs of their clients and use techniques that provide the best results in terms of both color vibrancy and hair health.