What term refers to the underlying color that emerges during the lightening process?

The term that refers to the underlying color that emerges during the lightening process is known as contributing pigment. When hair is lightened, especially through chemical processes like bleaching, it doesn't just become a lighter shade of its original color; rather, the underlying tones—those contributing pigments—become more visible. These pigments can affect the final color result after lightening, as they often represent the natural hues present in the hair prior to any alteration.

Understanding contributing pigments is crucial for barbers and stylists when formulating hair color, as they need to anticipate how these underlying tones will react and influence the overall appearance of the hair after a lightening treatment. This knowledge helps in achieving the desired shade and ensuring that the final look is harmonious and aesthetically pleasing. The other terms mentioned do not specifically refer to the colors that become apparent during the lightening process, which is why they do not fit the definition provided.