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
History of medicine in the Philippines used as wrappers of cigarette boxes, strips of banana frond, or wrappings of medicinal leaves. The type of "pull" felt during the massage therapy becomes the basis of what causes the ailment (i.e. the "smoothness" of the pull of the material used or the lingering or hovering or the strength of resistance of the applied material on a specific spot of the patient's body). The mangtatawas (literally "user of "tawas"") determines the cause and nature of illnesses through the use of potassium alum, locally known in the Philippines as "tawas" as one of the primary ingredients. The other materials used