Leon Battista Alberti.
CXLIV
A word as to colour. One can only give warnings against possible faults; it is clearly impossible to teach colour by words, even ever so little of it, though it can be taught in a workshop, at least partially. Well, I should say, be rather restrained than over-luxurious in colour, or you weary the eye. Do not attempt over-refinements in colour, but be frank and simple. If you look at the pieces of colouring that most delight you in ornamental work, as, e.g. a Persian carpet, or an illuminated book of the Middle Ages, and analyse its elements, you will, if you are not used to the work, be surprised at the simplicity of it, the few tints used, the modesty of the tints, and therewithal the clearness and precision of all boundary lines. In all fine flat colouring there are regular systems of dividing colour from colour. Above all, don't attempt iridescent blendings of colour, which look like decomposition. They are about as much as possible the reverse of useful.
William Morris.
CXLV
After seeing all the fine pictures in France, Italy, and Germany, one must come to this conclusion—that