White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White on television and computer screens is created by a mixture of red, blue, and green light. The color white can be given with white pigments, especially titanium dioxide. In ancient Egypt and ancient Rome, priestesses wore white as a symbol of purity, and Romans wore white togas as symbols of citizenship.
White supremacy is the belief that white people are superior to those of other races and thus should dominate them. The belief favors the maintenance and defense of any power and privilege held by white people. White supremacy has roots in the now-discredited doctrine of scientific racism and was a key justification for European colonialism. As a political ideology, it imposes and maintains cultural, social, political, historical, and/or institutional domination by white people and non-white supporters.
White privilege, or white skin privilege, is the societal privilege that benefits white people over non-white people in some societies, particularly if they are otherwise under the same social, political, or economic circumstances. With roots in European colonialism and imperialism, and the Atlantic slave trade, white privilege has developed in circumstances that have broadly sought to protect white racial privileges, various national citizenships, and other rights or special benefits.
White is a racialized classification of people generally used for those of mostly European ancestry. It is also a skin color specifier, although the definition can vary depending on context, nationality, ethnicity, point of view, appearance, etc. Description of populations as "White" in reference to their skin color is occasionally found in Greco-Roman ethnography and other ancient or medieval sources, but these societies did not have any notion of a White race or pan-European identity.
White nationalism is a type of racial nationalism or pan-nationalism which espouses the belief that white people are a race and seeks to develop and maintain a white racial and national identity. Many of its proponents identify with the concept of a white ethnostate. White nationalists say they seek to ensure the survival of the white race, and the cultures of historically white states. They hold that white people should maintain their majority in majority-white countries, maintain their political and economic dominance, and that their cultures should be foremost in these countries.