I've been reading "The Elements of Color" by Johannes Itten:

"Between black and white there throbs the universe of chromatic phenomena. So long as we can perceive them and recognize their relationships; their inner essence remains concealed from our understanding, and must be grasped intuitively. Hence rules and formulae can be no more than signposts on the way to color fulfillment in art.
In his Trattato della Pittura, which sets up a formidable array of rules for painters, Leonardo (Da Vinci) remarks, "Didst thou attempt to create by rule, thou shouldest accomplish nought, but devise only confusion." Thus he relieved his readers once more of the encumbrance of knowledge, and encouraged them to follow their intuition.
It is not the means of expression and representation that count in art, but the individual in his identity and humanity. First comes the cultivation and creation of the individual; then the individual can create."

Interesting focus, thorugh the archaic English, on individuality.