What are the tiny grades of pigment surrounded by melasomes in the hair's cortex that create natural hair color?

The tiny grades of pigment responsible for creating natural hair color are known as melanin. Melanin is produced in specialized cells called melanocytes, which are found within the hair follicles. These pigments are encapsulated within structures called melasomes, which allow the distribution of color throughout the hair shaft.

Different types of melanin contribute to a variety of hair colors: eumelanin, which can be either black or brown, and pheomelanin, which provides yellow or red hues. The unique combination and concentration of these melanin types result in the natural range of hair colors observed in individuals.

The other options pertain to different aspects of hair or color theory. Chromatophores are pigment-containing cells found in certain animals, mainly associated with color changes in their skin rather than hair. Keratin is a protein that forms the structure of hair, nails, and skin, providing strength and texture but not color. Hue refers to a particular shade of color but does not specifically identify the pigment involved in hair coloration.