Color Hair color resides in the cortex. Though keratin, the maincomponent of hair fibers, is colorless,melanin, also foundin the cortex, is responsible for characteristic hair color.Melanin granules are formed in the melanocytes at thebase of the hair follicle (the dermal papilla), which secret emelanosomes into keratinocytes.In the anagen phase,melanosomes are transferred to cells in the cortex and themedulla,but not the cuticle.Melanin granules are spread throughout the cortex, more densely so in its outermostpart,yet do not enter the cuticle. Therefore, to alternatural hair color effectively, hair cosmetics need to getbeyond the cuticle into the inner part of the hair shaft.