Art is harmony. Harmony is the analogy of contrary and of similar elements of tone, of color and of line, conditioned by the dominate key, and under the influence of a particular light, in gay, calm, or sad combinations.
Source: Letter to Maurice Beaubourg, 28 Aug 1890.
-- Georges Seurat, (Dec 2 1859-1891), French artist, painter; He devised the pointillist style of painting using tiny dots of color.