The photographic image of Un Dimanche après-midi à l´Île de la Grande Jatte A Sunday Afternoon on the Island of La Grande Jatte shows how Georges-Pierre Seurat (1859-91) carefully added colour to his figures, to the foreground, and also to the foliage of the trees to create vibrancy. Seurat is known to have avoided earth colours on the surface and relied on pure tints which he arranged on his palette in the order of the spectrum of visible light: they are used here to create a mesh of colour within the precise contours, geometric shapes, and measured proportions and distances of the painting.
During restoration of Michelangelo's Sistine Chapel ceiling the muted colours, dulled by the centuries, went - to be replaced by more saturated colours - this new scheme of things came as a shock to many. Graphic display computer programmes work with what are called primitives echoing the concept of "primitive" i.e. saturated colours. Seurat's technique added colours to the canvas unmixed. To soften the effect of saturated blocks of colours, the colours are blended optically. Computer programmes can blend in pixels of saturated colour to create a Pointillist sketch.