Illustrated books


©2003 David Kidd

Jimi Hendrix saw a "purple haze" in 1967, but Isaac Newton saw "indigo, violet" in 1665. What shall we say in today? For three centuries all school children had Newton's formula "the colors of the rainbow are red, orange, yellow, green, blue, indigo, violet" drummed into them. But since children can't ever find any indigo paint what did Newton mean by indigo? And another thing: all modern color wheels have six divisions, not seven, so why did Newton led us astray with seven colors?

The answer is that indigo is a dark warm blue that video technology calls blue, and what Newton called blue is what printers now call cyan. By magenta they mean what Newton called red, and what video technology calls red Newton would consider almost orange. See my COLOR WHEEL web page where I explain how the meaning of the color names has changed in the RGB and CMYK systems, and where I propose a new set of colors of the rainbow to teach our children.


In fact Newton's spectrum of seven spurred Goethe to write a book in retaliation:"Farbenlehre" in 1810. Goethe's "theory of color" describes simple experiments that prove there are only three primary colors, and that they are equally spaced by three secondaries, making six. The one he drops is indigo. Goethe's dramatic writing was as much stimulated by Newton's Seven as it was by the legend of Faust. Goethe said "no aristocratic presumption has ever looked down on those who were not of its order, with such intolerable arrogance as that betrayed by the Newtonian school...looking down with a supercilious air on the ancient and less modern inquirers" (preface xlv).

Sir John Leslie suggested that "when Newton ... ventured to assign the famous number seven he was apparently influenced by some lurking disposition towards mysticism .... betrayed by a passion for analogy, when he imagined that the primary colors are distributed over the spectrum after the proportions of the diatonic scale of music, since those intermediate spaces have really no precise or defined limits" (59). However I believe that Newton's Seven was more inspired by the writings of Jacob Böhme for his visionary books also inspired in Newton the discovery of gravity (Roob 253). Böhme had a mystical experience in 1600 stimulated by Genesis 1:5-2:3 and 7:1-8:12 where God creates and recreates the world in seven day periods. And because Böhme wrote that "light was born from seven source spirits" Newton wanted to make his discriminations fit that number.

In my opinion if Newton had studied the origin of the number seven more deeply he could have got it right at the beginning As you can read there, Judao-Christian tellers of religious allegories indiscriminately apply the time unit of seven to any quantity. Did Böhme and Newton misapply it to light? Oddly there is another connection between the number seven and the spectrum through the origin of words. Our word week is akin to the Latin word vicis that means alternation, and that is akin to the Greek word iris that means rainbow. This coincidence may be no accident, as tellers of the Deluge story traditionally indulge in word-play.


However Newton and Böhme neglected a church doctrine that the seven days of the scripture are made of six similar work days and then a special one that is quite different and set apart: a holy day. The week is not just a chain of seven equal and identical periods because one is described as both the origin and the total of the other six: "the reason for them" the church says. As Newton persisted in wanting his spectrum to have seven colors, his science could have fitted his theology better if he'd described it as six colors with the seventh one as their origin. By logical priority white is the first and total light, and if we apply the same rule to pigments the first and total pigment would be black. In either case when you look at the total you will see no colors in it because when diametric opposites are united they appear to neutralize each other, for example magenta and green make a gray.

However opposite colors concur in that they are both visible. Both origin and totality must contain all antinomic affirmations. In the linear spectrum the quality of visibility defines both the beginning and the end of the spectrum line. However the origin is not the same as the first because an origin is prior, and a total follows the last. That is: visibility is not a color; in the same way that a week is not Sunday. However one color could symbolize visibility in the same analogous way that Sunday represents the week.

In making the spectrum line into a color wheel there must be a location in the circle where the two ends of the line join: it falls between violet and red, and that color is called purple. Could it be that the One joins the split ends so that purple is made of the two colors at once? A sketch I drew surprised me by looking like the Greek letter Alpha. I soon found out that Omega also makes a good design.
The color circle is more like a flask than a circle because it has an opening at the top. Could purple symbolize the origin and total of colors if it is embraces more than one color?

Lets examine the color purple and its current usage. Fresnel (1788-1827) did experiments established that light can be described as waves of different lengths: this is his solar spectrum with the wavelength in nanometers:
700 magenta620 red590 yellow560 green485 cyan465 blue425 violet400

Lets define what were talking about: it's the colors that lie between blue and red on a color wheel. More precisely between violet and magenta. The tertiary color that lies there is called purple by Websters Dictionary and Roget's Thesaurus. Here are the colors we'll discuss:


primary blue




 primary red

Purple is nearest to red, and on the blue side of the middle is violet, and indigo you'll find it is very near to blue. When I was looking for other samples of office printer paper to show you I found an interesting thing. These are all the commonly available papers I could find between blue and rose:

blue violet azure lilac lavender orchid  purple mauve lilac rose

I found that every manufacturer makes a paper on the blue side, but only one manufacturer makes a paper called purple. Between purple and rose I found few papers. Manufacturers always say that they can only make what the customers buy because if nobody buys a color they have to stop making it. Obviously very few people want to use purple, and nobody seems to want purple-red paper. Why is that? Fashion is always a factor, so maybe purple will make a comeback in the future. But it seems to me that currently people just don't really like purple when they see it. They may ask for purple, but if you give them a choice of many colors between blue and red they always pick the violets: the ones on the blue side.




Steven M. Boker from a University Psychology Department writes "Newton should be credited with the first model of perceptual color space, essentially a color wheel with white in the center (see Figure 1). This type of two dimensional slice through a color opponent space has persisted in most formulations of perceptual color representation to this day." for more read:

How do we see in color?
The Rochester Institute of Technology writes
"In the retina of our eye are photoreceptors that are sensitive to light. When light is absorbed by the photoreceptors, the light energy is converted into electrical and chemical signals that the neurons in our eye and brain process. There are two kinds of photoreceptors in the retina: rods and cones. Rods mediate vision at lower levels of illumination. Cones mediate vision at higher levels of illumination. There are three types of cones with each type differentially sensitive to a different region of the visible spectrum. They are known as the Long-wavelength sensitive cones, the Middle-wavelength sensitive cones and the Short-wavelength sensitive cones. Sometimes they are referred to as R-, G-, and B-cones but these are misnomers based on the colors in the spectrum. For example, very short wavelength light can uniquely stimulate the B-cones but the sensation associated with this light stimulation has a reddish and bluish component. Fundamentally our color vision derives from comparisons between the amount of light being absorbed by each cone type. Our visual system compares the outputs of the cone types to process color. In addition, color appearance is influenced by the ratios of cone excitations in surrounding regions and by the overall levels of cone excitation caused by the prevailing illumination. These comparisons occur at different stages of processing that start in the retina and continue to the cerebral cortex of the brain."
Read more at:


Austen Clark writes "The possibility that what looks red to me may look green to you has traditionally been known as "spectrum inversion". This possibility is thought to create difficulties for any attempt to define mental states in terms of behavioral dispositions or functional roles. If spectrum inversion is possible, then it seems that two perceptual states may have identical functional antecedents and effects yet differ in their qualitative content. In that case the qualitative character of the states could not be functionally defined" Those who love logic can read the rest at:

Darren Meyer says "What we perceive as color is really differences in the wavelength of light. Many colors can be generated by a single wavelength of light, such as red and green. Other colors can only be produced by light containing a number of wavelengths, such as purple and pink. To describe the wavelengths contained in a color a spectral density curve can be drawn. This is a graph that has wavelengths along the x axis and light intensity along the y axis. Colors that are produced with a single wavelength have all their intensity at a single spot on the x axis, while other colors contain a mix of wavelengths. This is illustrated in the following diagram."
Read more at:
However I think that the second graph that Meyer shows above does not illustrate purple, because purple is not not a collection of adjacent wavelengths but is made of colors from the opposite ends of the x axis, something like this:

Violet was originally from the flower Violacea: its color is a dark blue red of medium saturation.

Indigo however is a dye C16H10N2O2 from a leguminous herb Indigofera found in India whose color is very dark blue with a coppery luster: I could only find one sample of indigo paper:

 Indigo paper

I believe that what Newton meant by indigo is what modern engineers call Blue in the RGB system

dark Blue in RGB

Purple dye was always an expensive specialty. Near their port of Tyre the ancient Phoenicians collected gastropod molluscs of the genus Purpura that yielded the pigment. The Greeks and Romans took a robe dyed purple to be an emblem of rank or authority. Goethe reminds us that "The Roman emperors were extremely jealous with regard to their purple"(840) and made it against the law for other people to wear it. Purple still signifies imperial or exalted rank. Even today this color is worn by the popes and bishops. Here are names of various kinds of purple: bishop's purple, imperial purple, king's purple, monsignor purple, pontiff purple, regal purple, royal purple. These associations with glorification and pride may provide a psychological reason for common people to avoid it. As an adjective purple on the negative side means obtrusively ornate, highly rhetorical, or marked by profanity.
Bibliography of Tyrian purple: Dyes in History and Archaeology

Kimura M, Sakamoto K, and Fujii H:
Studies on identification of the natural dyes on the textiles from at-Tar caves al-Rafidan, 1993, 14, pp141-148. 2000 year old samples of Kermes and Tyrian purple / indigo dyes on wool are distinguished by UV/VIS spectra following extraction with dimethylformamide and DMF-NaOH solutions giving wavelength maxima at 550-600 nm (two peaks) and 600-620 nm respectively.

Taylor G W:
Detection of shellfish purples on textiles on Historical and Archaeological Textiles, 1983, 2, pp20-21. Purple pigment was extracted with pyridine, diluted with water and extracted into ether. The ether evaporated and the residue taken up in methanol for spectroscopy. Wavelength maxima in pyridine: indigo, 615 nm, dibromoindigo 605nm; in methanol, 610 and 600 nm respectively.

Read more at:


Of red-blue Goethe writes "Blue deepens very mildly into red, and thus acquires a somewhat active character, although on the passive side... It may be said to disturb than enliven. ... so we feel an inclination to follow the progress of the color... to find a point to rest in. In a very attenuated state, this color is known to us under the name of lilac; but even in this degree it has a something lively without gladness. Blue-Red: This unquiet feeling increases as the hue progresses.... On this account, when it is used for dress, ribbons, or other ornaments, it is employed in a very attenuated and light state, and thus it displays its character as above defined, in a peculiarly attractive manner. As the higher dignitaries of the church have appropriated this unquiet color to themselves, we may venture to say that it unceasingly aspires to the cardinal's red through the restless degrees of a still impatient progression."(787-791)


Looking at printing inks to see what the popularity of colors is in respect to print, these are the only ready-mixed colors I could buy between blue and red:

process blue, reflex blue, navy blue, fast blue lake, violet,  purple, rhodamine red

Once again notice a plentiful range on the blue side, but a shortage on the red side. Is there also a scientific reason for this? Perhaps there is, because Websters largest dictionary says "As analyzed in terms of appearance, most colors have a hue that more or less resembles one of the hues in the spectrum.... The purple hues, while not found in the spectrum itself, show a resemblance to the blue and red ends and complete the color circuit." (448).

So purple is not in the spectrum? How can that be? Don't scientists tell us that we see by the light of the sun? So how can we see a color that isn't there? But if the color spectrum is a straight line becoming invisible at each end, how is it that we can join the ends together by joining violet to red? The spectrum scientists see from their prisms show that violet is the terminus, and if you want to find red you have to go back to the beginning. So purple doesn't make sense to a scientist because violet and red are opposite extremes. However Newton's diagram clearly shows that he believed that violet joins the ends together and it looked OK to him. Thanks to this diagram all artists see the colors in a circle not in a straight line, and the extreme differences somehow become complementaries.


 CIE 1931 Chromaticity Diagram

Charles A. Poynton says "A color plots as a point in an (x, y) chromaticity diagram. When a narrowband SPD comprising power at just one wavelength is swept across the range 400 nm to 700 nm, it traces a shark-fin shaped spectral locus in (x,y) coordinates. The sensation of purple cannot be produced by a single wavelength: to produce purple requires a mixture of shortwave and longwave light. The line of purples on a chromaticity diagram joins extreme blue to extreme red. All colors are contained in the area in (x, y) bounded by the line of purples and the spectral locus."
Read more at:
Here is an online test for color vision by Dr. Shinobu Ishihara.
Penstarsystems says
"Cones are the second cell type, and these are much more complex. There are three basic parts to them that absorb different wavelengths of light and release differing amounts of different neurotransmitters depending on the wavelength and intensity of that light. Basically there are three receptors in a cone that absorb red, green, and blue wavelengths of light. Each of these receptors release a different neurotransmitter for the color, with differing amounts of the neurotransmitter depending on the intensity of the wavelength. Purple is a combination of blue and red, so the red and blue receptors would release differing amounts of neurotransmitter, while the green wouldn't release any. This information then passes onto your visual cortex and we "see" purple."
More at:


We find this curious principle of consensus of contradictions also recognized in the history of metallurgy. Following the Sumerian observations from stars, in ancient Alchemical texts the seven metals were synonyms for the seven planets:

 gold  silver  mercury  copper  iron  tin   lead
 Sun  Moon  Mercury  Venus  Mars  Jupiter  Saturn

Notice that the heaviest metals, gold and lead, are at either end. Alchemists tying to make gold always put lead in their concoction to give it the same great density that gold has. The elements lead and gold are in fact very close on the modern scientist's table of elements although distant at the scrap dealers. So the early scientists were aware that the opposite ends of any aspect of existence are similar in a strange manner. Indeed, the idea for a circle of colors is first seen in Alchemical illustrations of Ouroboros, the self-consuming dragon. This dragon was drawn in a circle around the tangible world, eating its own tail, representing how the beginning consumes the end. We should paint a dragon with a magenta-head, a red neck, orange shoulders, a chest of yellow, belly green, pelvis of cyan, hind legs blue and tail violet.

This mystical circling is reminiscent of the twentieth Century "doughnut theory" of the universe which conjectures that if you could see far enough into space in one direction you would see the back of your own head. This red head eating its own violet tail is a metaphor for how the ends of the spectrum could join into a circle. Modern scientists struggle to explain how these two ends can meet. They say that below red's low frequency lies infra-red, and above violet lies ultra violet, both extremes being invisible frequencies to the human eye. It seems to me that somehow this sharing of invisibility joins them in vision. But considering that other creatures see wavelengths that we do not see, we might conclude that purple is a product of human eyeballs, not of nature itself. When we see a purple color either we are seeing two visible colors overlapping, or two invisible colors interacting to become visible.



All material on this website, unless otherwise marked, is copyright ©2002-3 David Kidd
Böhme, Jacob. Theosophische Werke. Amsterdam: 1682.
Boker Steven M. Dept of Psychology, University of Virginia. The Representation of Color Metrics and Mappings in Perceptual Color Space. Charlottesville <> accessed 24 Dec. 2002.
Clark, Austen. Department of Philosophy. University of Connecticut. Spectrum Inversion and the Color Solid. Storrs, 1985. <>. accessed 24 Dec. 2002.
Cooksey Chris: Dyes in History and Archaeology 1994 <> accessed 27 Dec. 2002.
Goethe, Johann Wolfgang. Theory of Colors. Trans. Charles Lock Eastlake. London: Murray, 1840. Reproduced Cambridge: Massachusetts I. T, 1970.
Ishihara, Dr. Shinobu. Tests For Color Blindness. <> accessed 24 Dec. 2002.
Leslie, Sir John. Treatises on Various Subjects of Natural and Chemical Philosophy. (59). quoted in Goethe Theory of Colors (xxxii).
Meyer, Darren. WPI, CS Department. Color Theory and Pre-Press
<> accessed 24 Dec. 2002.
Penstarsystems, LLC The Human Eye (and Visual Cortex). Laramie: <> accessed 27 Dec. 2002.
Poynton,Charles A. What are CIE x and y Chromaticity Coordinates? ©1997 <> accessed 12/27/02
Roget's international thesaurus. Ed. Peter Mark. New York: Harper & Row, 1977.
Munsell Color Science Laboratory. Rochester I. T. How do we see in color? Rochester: <> accessed 24 Dec. 2002.
Roob, Alexander. Alchemy & Mysticism. Köln: Taschen, 1997.
Wilcox, Michael. Blue and Yellow Don't Make Green. Cincinnati: North Light, 1987.
Webster's Third New International Dictionary. Springfield: Merriam,1976.


To go back to what we teach our children: "Roses are red, Violets are blue, Sugar is sweet, And so are you" But why do we say violet is blue? Is it because many people are color blind and do not see the purple in the spectrum? Since purple is made of red and violet, the colors on the extreme edges of visibility, any disfunction or infirmity in our optical system would be most likely to obscure purple. In conclusion other names for purple make a list of precious stones, delicious fruit and charming flowers. In enjoying these are we seeing beyond the visible world?

 amethyst aniline  burgundy  clematis fluorite
 red grape gridelin  heliotrope  hortense hyacinth
 lilac livid madder  magenta  mallow mars violet
 mauveine methyl violet  mulberry  orchid pansy
 prune raisins  sloe  solerino Tyrian
 crimson  fuchsia   lavender  mauve  plum
 wine purple        (Roget 373.4)