In 1666 AD, Isaac Newton passed a ray of sunlight through a prism and split the white light into a rainbow spectrum of colors.
red, orange, yellow, green, blue, indigo, violet ...
All of these colors of light waves have their own unique wavelength.
 | But there is no brown color in the spectrum! |
| no such thing as the wavelength of brown |
| "brown" is our internal representation of the mixture of other colors |
| the color brown is our invention, and begins and ends within our mind |
| brown (and in fact all color) is the way our mind represents the physical property of the wavelength of a light wave |