Fauvism
A short-lived but highly influential French art movement (c. 1904-1908) characterized by wild, non-representational color used for purely expressive effect -- critics called the artists 'Les Fauves' (The Wild Beasts).
Fauvism shocked the Paris art world when Henri Matisse and his circle exhibited together at the 1905 Salon d'Automne. Critics were appalled by the violent, non-realistic color -- a portrait might show a face with a green nose and an orange shadow. One critic dubbed them 'les fauves' (wild beasts), intending it as an insult. The artists kept the name.
The key Fauvist insight was that color could be completely liberated from descriptive function. A tree didn't have to be green; a shadow didn't have to be darker than the object casting it. Color was free to be whatever the painter felt, whatever created the most powerful pictorial effect.
Fauvism was brief -- by 1908, most of its practitioners had moved in different directions. Matisse continued to develop his color approach into the lush, decorative Fauvist aesthetic that defines his mature work. Derain and Vlaminck moved toward Cubism. But the liberation of color that Fauvism achieved permanently changed painting.