The nature of colored light was the subject of many disputes. Painters like Leonardo da Vinci devised their theories of colors from experiments with combinations of pigments. However, pigments behave in a way which is fundamentally different from the colors of light. Light is the source of all colors, while pigments reflect, absorb or transmit the colors of the light.

Newton's seven number scale fits in beautifully with the seven musical tones, and indeed the association of color with sound was noted many centuries beforehand by Aristotle in his book De Sensus (The Senses). Vicenzo Galilei (Galileo Galilei's son) attempted to put together a color piano which linked colors to musical tones. Certain theories link tones and colors as follows: Do (C) = deep purple, Re (D) = purple, Mi (E) = red, Fa (F) = orange, Sol (G) = yellow, La (A) = green and Si (B) = blue . see more.
The correspondence between color and music belongs to the field of the psychology of color vision.
Newton's scientific approach was stubbornly rejected by leading figures in the field of art who disregarded the relationship between light which is the source of colors, and the illuminated material reacting to the colors of light, and the visual system which receives and decodes the color. A most prominent figure in the attack on Newton's color theory was Johann Wolfgang von Goethe (1749-1832), a poet, playwright, stage director, philosopher, lawyer and natural scientist.

In 1810 Johann Goethe published his book Zur Farbenlehre ("The Theory of Color"), in which he attacked Newton's theory of color, proposing a theory of his own. Goethe's criticism of Newton was venomous, and opened with an attack on Newton and his theories as "...universal nonsense fantasies, a fable with a flea in its ear". Goethe returned to the theories of Aristotle and Leonardo da Vinci, who postulated that the phenomenon of color is a visual creation of the human eye which allows man to perceive color, and not an intrinsic quality of light.

Geothe's concept of color is typical of an artist's point of view, based on the psychology of vision. He disregarded any scientific proof of the spectral makeup of white light, and in his own experiments looked at a white wall through a prism, discovering that the wall appeared white. Consequently, Goethe developed a color theory which claimed that white light is the primary light in nature, and that colors are produced by dimming this light with the help of "dark mediums" through which it passes. Goethe maintained that: "The eye does not perceive an object unless it is bright, dark and colored, which together make up all that allows the eye to distinguish between one object and another, and between different parts of an object".
Goethe divided colors into the following categories:

Positive colors (Yellow, yellow-red, etc.) which affect feelings, sense of life, ambition.
Negative colors (Blue, blue-red, crimson, etc.) which arouse restlessness and worry.
Modulating colors which subtract or add to any of the color groups in accordance  
with the colors in the mixture.

Two of Goethe's works on light are still of interest to the contemporary lighting designer: the first - a paper discussing shadow and the colors created in shadow, and the other - a paper on the relationship between colors and their emotional and symbolic significance.