Some of them are clean-shaven, but others—especially those of high rank—shave their cheeks but leave a moustache that covers the whole mouth...".During the medieval period, Spanish women preferred to dye their hair black, yet by the time of the Renaissance in the 16th century the fashion (imported from Italy) was to bleach their hair blond or dye it red. Between the Renaissance and the Enlightenment, a number of dangerous hair bleaching methods remained widely practiced, including the use of sulfuric acid, which was an accepted form of hair coloring around the 1600s, and laying out in the sun with hair covered in lye a century later.In Sir Hugh Plats 1602 work Delightes for Ladies the use of oil of vitriol (sulfuric acid) to bleach black hair to chestnut is described as: "Take one part of lead calcined with Sulphur, and one part of quicklime: temper them somewhat thin with water: lay it upon the hair, chafing it well in, and let it dry one quarter of an hour or thereasbouts; the wash the same off with fair water divers times: and lastly with sope and water, and it will be a very natural hair-colour. The longer it lyeth upon the haire, the browner it groweth, This coloureth not the flesh at all, and yet it lasteth very long in the hair." Modern history
Howard Hughes 1931 movie Platinum Blonde starring Jean Harlow is noted to have popularized platinum blonde hair color in the US.
Hair bleaching products can damage hair and cause severe burns to the scalp when applied incorrectly or left on too long.Industrial bleaches that work by reduction (such as sodium hydrosulphite) react with a chromophore, the part of the molecule responsible for its color and decrease the number of carbon-oxygen bonds in it, making it uncoloured. This process might be reversed to a certain extent by oxygen in the air, such as yellowing of bleached paper if kept exposed to air. In contrast hydrogen peroxide chemically alters the chromophore so that it increases the number of carbon-oxygen bonds. Due to the relative absence of reducing agents in the environment, chromophores cannot restore themselves as seen in reduction-based bleaches.Bleaching the hair is a gradual process and different colors could be achieved dependent on the original hair color, application time, and strength of the product used. Applied on black hair, the hair will change its color to brown, red, orange, orange-yellow, yellow, and finally pale yellow. Toner
Toning is a common practice after bleaching to mask the undesirable red and orange tones of "brassy" hair using a toner dye. Through toning, the yellow hue of fully bleached hair can be removed to achieve platinum blond hair. The appropriate color of the toner depends on the color of the bleached hair; e.g. to remove the yellow tones a violet toner dye will be needed, but to neutralize red and orange hues a green and blue toner would be more suitable. Tinted shampoos can also be used to tone hair.