Color is the most personal of all the qualities the artist puts into his painting—by itself it might constitute his style. Beautiful, idiosyncratic, colors are part of every single great work of art.
Painting, according to the nineteenth-century critic John Ruskin, is essentially a choice of colors.
“I hope that enough has been said to show the nobility of colour….there is [no subject] that needs more to be insisted upon, chiefly on account of the opposition of the persons who have no eye for colour, and who, being therefore unable to understand that it is just as divine and distinct in its power as music (only infinitely more varied in its harmonies), talk of it as if it were inferior and servile with respect to the other powers of art: whereas it is so far from being this, that wherever it enters it must take the mastery……There is not any distinction between the artists of the inferior and the nobler schools more definite than this; that the first colour for the sake of realization, and the second realize for the sake of colour…….
“A painter’s business is to paint, primarily; and…all expression, and grouping, and conceiving, and what else goes to constitute design, are of less importance than colour, in a coloured work, and so they were always considered in the noble periods…..”
Ruskin, Selected Writings, Penguin Classics, pp.163-165. The italics are Ruskin’s.