Human hair color account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blond/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several gene pairs control the light versus dark hair color in a cumulative effect. A person's genotype for a multifactorial trait can interact with the environment to produce varying phenotypes (see quantitative trait locus). Natural hair color can be brown, blond, black, red, or white; all natural hair colors including grey, white and lightest blond, are shades of brown. The Fischer–Saller scale, named after Eugen Fischer and , is
Like Colour to the Blind Like Colour to the Blind Like Colour To The Blind (1998) is the third in a series of four autobiographical works by internationally bestselling autistic author Donna Williams. Once published in the US using the American spelling 'color', it is now published worldwide by Jessica Kingsley Publishers using the UK spelling 'colour'. It has been published in several languages worldwide. "Like Colour To The Blind" covers Williams' relationship and 'accidental marriage' to 'Ian', a man on the autistic spectrum as she exorcises the vast array of stored behaviours, responses, actions and phrases from her repertoire to discover what is left