Keratin is not a pigment, but rather a type of structural protein found in the skin cells. While keratin doesn't directly contribute to color, it plays a crucial role in the structure of hair and skin, which can indirectly influence their color.
For instance, hair contains melanin, a pigment responsible for its color. Melanocytes, specialized cells, produce melanin, which then travels through the keratin within the hair shaft.
Keratin's structure also affects the way light reflects off of it, contributing to the overall appearance of hair and skin. This is known as structural coloring. For example, the iridescent shimmer of some bird feathers is due to the specific arrangement of keratin molecules, rather than pigments.
Therefore, while keratin itself isn't a pigment, it plays a critical role in determining the color of various structures through its interactions with pigments and its influence on light reflection.
