what are the three color theories that seurat used in sunday afternoon park
The two main artistic traditions that dominated modern art during the second half of the nineteenth century – Realist painting and Impressionism – evolved from painters’ direct observation of the world around them. In contrast, Georges Seurat based his painting on the theories of Divisionism (a scientific interpretation of how the eye sees colour), pioneered by Michel Eugene Chevreul, Ogden Rood and others. The two large genre paintings that made his reputation – Sunday Afternoon on the Island of La Grande Jatte and Bathers at Asnieres – are perfect examples of his ‘new’ Impressionism – although calling it after Monet’s style of spontaneous plein-air painting is rather misleading. Seurat worked mostly in his studio and planned his compositions with meticulous attention to detail. Indeed, for La Grande Jatte he made over seventy preliminary drawings and oil sketches. For more on the impact of Seurat’s Neo-Impressionsm, see Italian Divisionism (1890-1907). For more about the two main traditions, and how they related to each other, see: Realism to Impressionism (c.1830-1900).
In 1881, after studying at the Ecole des Beaux-Arts, followed by a short spell of military service, Seurat opened a small painter’s studio in Paris while continuing his studies on the tonal effects of colour, with a series of conte crayon drawings. He was determined to develop an intellectual style of painting that would open up new possibilities for art. The technique he settled on – later nicknamed ‘Pointillism’ by the art critic Felix Feneon (1861-1944) – involved the use of small touches of pure colour, which are not mixed but placed side by side on the canvas. When viewed from a certain distance, these touches of colour blend together. In effect, the colour pigments are mixed together by the eye, rather than by the artist. The whole idea is to make the colours more luminous and shimmering than they would be if mixed on the palette. See also: Colour Theory in Fine Art Painting.
Divisionism is a broader term meaning that it is possible to obtain brighter hues of color such as green, orange and purple, by a series of dots (or blobs) of both primary colors so that they are optically intermingled in the spectator’s eye (rather than being pre-mixed). The artists prefer the term Neo-Impressionism (again, coined by a critic — this time Felix Feneon) as a description of their work.
Sunday Afternoon on the Island of La Grande Jatte (Un dimanche après-midi à l’Ile de la Grande Jatte), Georges Seurat, 1884-1886.
In the 1950s, historian and Marxist philosopher Ernst Bloch drew social and political significance from Seurat’s La Grande Jatte. The historian’s focal point was Seurat’s mechanical use of the figures and what their static nature said about French society at the time. Afterward, the work received heavy criticism by many that centered on the artist’s mathematical and robotic interpretation of modernity in Paris. 
In Topiary Park (formerly Old Deaf School Park) in Columbus, Ohio, sculptor James T. Mason re-created the painting in topiary form;  the installation was completed in 1989.
- Material pigments: Red + Yellow + Blue = Black
- Optical / Light : Red + Green + Blue = White
Georges Seurat first studied art at the École Municipale de Sculpture et Dessin, near his family’s home in the boulevard Magenta, which was run by the sculptor Justin Lequien.   In 1878 he moved on to the École des Beaux-Arts where he was taught by Henri Lehmann, and followed a conventional academic training, drawing from casts of antique sculpture and copying drawings by old masters.  Seurat’s studies resulted in a well-considered and fertile theory of contrasts: a theory to which all his work was thereafter subjected.  His formal artistic education came to an end in November 1879, when he left the École des Beaux-Arts for a year of military service. 
La Grande Jatte, toward Clichy, 2006, via wikipedia.org
Nonetheless, the now-famous eighth Impressionist exhibition prided itself on being at the cutting edge of new styles and movements, so Seurat’s Grande Jatte fitted that mold perfectly.