Ace the South Dakota Cosmetology Test 2026 – Style Your Future with Confidence!

The cortex is the essential part of the hair that contains the pigment, which determines the hair's color. This middle layer makes up the majority of the hair's structure and is composed of long chains of protein called keratin. Within the cortex, there are specialized cells known as melanocytes that produce melanin, the natural pigment of the hair. The type and amount of melanin present in the cortex will dictate whether the hair is blonde, brown, black, or red.

The cuticle, which is the outermost layer of the hair, serves as a protective barrier and does not contain any pigment. The medulla, which is the innermost layer, may or may not be present in all hair types and also does not hold pigmentation. The term 'strand' typically refers to the entire hair fiber but is not a specific layer that holds pigment. This highlights the integral role of the cortex in not only the structural integrity of the hair but also in its coloration.