Every head of hair contains hairs of different thickness and shape, as well as a variety of colours, although this will sometimes be so slight that the eye will not notice it.
Europeans have on average one hundred thousand hairs on the head, varying in shape, size and colour. The general colour range is from medium blonde through to medium brown.
Asian or African hair on the other hand has pigment within the cuticle as well, which accounts for the colour being so dark. Melanin particles are distributed throughout the hair shaft from the inside outwards. There is more pigment in the outer layers of the cortex than the inner ones. In naturally red hair, the pigment is often concentrated towards the centre of the cortex.
The second type of pigment is darker in colour, appears brown through to black. This is reasonable for depth. Depending on the amount of pigment hair can vary in colour from lightest blonde to darkest brown, appearing almost black. This pigment is called eumelanin (Brown-black pigment).

Black Hair – Dense & dark

Magnified Hair – Both same colour

High concentration of eumelanin smaller concentration of pheomelanin

Enlarged version of distribution of pigment
Natural pigment sits in cuticle & the cortex. Easier to lift.

Pigment Cell – Melanocyte –
Granular in shape eumelanin melansome