White is the lightest color and is achromatic (having no hue ), because it fully reflects and scatters all the visible wavelengths of light . It is the color of fresh snow , chalk , and milk , and is the opposite of black .
In ancient Egypt and ancient Rome , priestesses wore white as a symbol of purity, and Romans wore a white toga as a symbol of citizenship. In the Middle Ages and Renaissance a white unicorn symbolized chastity, and a white lamb sacrifice and purity. It was the royal color of the Kings of France , and of the monarchist movement that opposed the Bolsheviks during the Russian Civil War (1917–1922). Greek and Roman temples were faced with white marble , and beginning in the 18th century, with the advent of neoclassical architecture , white became the most common color of new churches, capitols and other government buildings , especially in the United States . It was also widely used in 20th century modern architecture as a symbol of modernity and simplicity.
According to surveys in Europe and the United States , white is the color most often associated with perfection, the good, honesty, cleanliness , the beginning, the new, neutrality, and exactitude. White is an important color for almost all world religions. The Pope , the head of the Roman Catholic Church , has worn white since 1566, as a symbol of purity and sacrifice .