Symbols, Shapes and Colours
David Fontana: "Shapes and colours are the building blocks of all visual symbols, but are also significant in their own right." Already in the paleolithic era, abstract symbols like quadrangles, spirals, circles, lines of dots, etc. were used, often to represent higher forces.
Some theories, like sacred geometry, attribute even more importance to shapes and colours, as they see them as the very building blocks of reality itself.