Question: Why does our hair turn grey as we grow older?

Urslaan Chohan answered on 14 Jun 2018:

I can have a wild stab at this, as I am not a biologist! White light is a mixture of all the different base colours (red, orange, yellow, green, blue, indigo, violet). These base colours are at certain wavelengths. The colours we see is caused by certain wavelengths of light being absorbed by an object, leaving over certain wavelengths that mix and cause a colour to appear. For example, green is a mixture of red and blue light. Now, applying this to hair colours, the different hair colours is caused by certain wavelengths of light being absorbed by the hair and the remaining colours being absorbed. White hair is then where no wavelengths get absorbed, and all the mixture of all the colours gets reflected into our eyes. A chemical in the hair does the absorbing of wavelengths, which is a protein called melanin. This is the same protein that gives your skin its colour! So in white hair, this protein is missing; the body stops producing it as the body ages.