THE HUMAN QUEST FOR BRIGHTER COLORS
This is my first commentary on “The Human Quest for Brighter Colors,” an ongoing conversation on color science for visual artists and designers. The goal is to re-establish the role of color science in artists’ education using a short essay format. Knowing how color works and chemical composition of colorants can significantly increase artists’ ability to actualize the miraculous potential of the mind to experience color beyond the psycho-social and symbolic realms.
COLOR SCIENCE is a 450 year old interdisciplinary applied science combining the physical, chemical and psychological aspects of how humans see color; how our eyes interact with a limited array of the electromagnetic spectrum; and the colorants - pigments and dyes, humans use to change colors on surfaces.
Color vision is a result of human eyes’ capacity to receive frequencies in a narrow range of the electromagnetic spectrum, which is a stream of mass-less photons (particles) traveling in wavelengths at the speed of light. “White light” is a mixture of all visible wavelengths. White light can be dispersed through a specific prism to reveal colors in six hues: violet, blue, green, yellow, orange and red.
“Hue” and “color” are not interchangeable words.
A HUE is a bandwidth of frequencies in the human visual spectrum.
A COLOR is a single frequency in a hue.
Most humans easily imagine a single color for “yellow.” And yet we all do not see the same color to define the yellow hue. I have witnessed drunken painters come to blows over which of the cadmium yellows is really “yellow.” There is no single color that defines a hue.
Hue is conceptual and color is actual.
Because white light is composed of all frequencies in the human visual spectrum, its color frequencies can be separated (dispersed) by angles of refraction and velocity (speed). Color results when white light is refracted (bent) while passing from one transparent media to another (air to water) and its speed changes. White light’s speed slows down when entering a denser media like linseed oil and speeds up through less dense media.
Different frequencies move through media at different speeds so the angle of refraction (degree of bending) is different for different colors. Color frequencies in the violet hue, for example, are bent the most because violet light has a shorter wave length. Shorter waves travel faster and scatter more than longer waves. Wavelengths in the red hue are bent the least.
The green hue has the largest bandwidth of frequencies and the most colors. Being able to see green colors is a critical human survival skill because we must find water. After humans stood up over the savannah, we lost our connection. No longer able to smell it, we adapted by developing color receptors in our eyes that select for green frequencies. Where there is vegetation there is water. Human eyes specialize in seeing colors from the inner edge of blue/green into green/yellow.
In addition to signaling water, colors also signal food. Trees and plants signal human beings when food is ripe. We can see the simultaneous contrast of red apples hanging among green leaves more clearly than unripe apples which are hidden in the foliage. When pumpkins turn orange we make pie. We receive more frequencies in green, yellow, orange and red than in the shorter waves of blue and violet colors.
Our eyes work on the same principles as rainbows. Light travels through the air until meeting a transparent media like the cornea. The cornea changes the speed of light and its angle of refraction. Light is refracted again by the transparent vitreous fluid in the chamber of the eyeball then focused on the retina. The retina is considered part of the brain because it develops from the embryonic forebrain. The retina houses the photoreceptors - rods and cones, which are embedded in it like spark plugs in an engine.
Rods initiate vision when even a single photon of light enters the eye. They are rod-shaped, our original mammalian photoreceptors that “see” the relative value between brightness and darkness. Essential for vision in low light situations, rods work best at twilight and dawn. Hunters rely on this value-based vision to see movement along the horizon.
Cones are cone-shaped photoreceptors with the potential to receive six million frequencies - six million colors. Cones work best in full sun light when humans need to see fine details and subtle variations in color. Color vision drops off in low light situations and as we age. Visual artists may want to make a habit of jiggling the eyes a few times a day to keep muscles strong.
Follow link to Dr. Helga Kolb’s work on Webvision for detailed descriptions on human vision and fantastic graphics. Dr. Kolb is a visual artist as well as vision scientist. The author skillfully explains complex chemical reactions like how human eyes stay cool while constantly being bombarded by electromagnetic energy.
Newton and Goethe as Collaborators
Human eyes receive color frequencies via transmitted, reflected and emitted light.
Transmitted light streams through transparent media like air, water and paint binder until it reflects off an opaque surface.
Reflected light is composed of color frequencies reflected off an opaque surface.
Emitted light is a release of color frequencies stored in stone or pigments.
Human obviously knew before the 18th century how to use crystal prisms to project the hues of the rainbow. But the process was considered accidental and antidotal until Sir Isaac Newton (1642 - 1726) discovered the precise angle, probably by accident, which splits white light into the six hues. It was astronomy that obsessed Newton, not color. In 1661 after Cambridge was closed for two years due to plague, Newton had to move home and lost access to the lens grinders who made lenses for his telescope. Rather than wait he attempted to grind his own lens. He missed that angle but hit the angle that split white light into the full color spectrum. His discovery explained the physics of transmitted light - massless photons streaming at the speed of light.
A hundred years after Newton published his OPTICKS in English, Johann Wolfgang von Goethe (1749 - 1832) published his THEORY OF COLOURS in German. His THEORY OF COLOURS did not reach a wide audience because British color scientists rejected Goethe’s “polemic against Newton” and one of Goethe's key theses was lost in translation or lack there of.
Newton was interested in the physics of color while Goethe was interested in its physiology and psychology. Goethe challenged Newton’s emphasis on transmitted light and color at maximum. Goethe asked where was the consideration of “value” - relative brightness and darkness. Value is a property of reflected light not transmitted light. By the property of value, human perceive depth on a 2D plane. By adding black and white to the palette as colors, visual artists can create the illusion of dimension. Maybe Goethe was not challenging Newton at all, he was revealing the distinction between transmitted and reflected light.
During medieval times painters established the limited palette using colorants in only three hues: Red + Yellow + Blue. Primarily their goal was the use as few valuable colorants to mix as wide an array of secondary colors as possible. They used a few red colors, mostly earths + a few yellow colors, mostly earths + an occasional blue and mixed them with black and white colors to facsimiled colors in the violet, green and orange hues. A limited palette is cost effective.
Colors in transmitted light are not limited to colorants available - light is constantly streaming color frequencies of all six hues. Color scientists since the 1700s have used Newton’s theory of transmitted light to develop devices to split and refocus light. By the 20th century, they had invented microscopes, oscilloscopes, visual light communication, LED and now the devices we hold in our hands. I cannot explain why color scientists, in particular, Thomas Young, who first observed that photons of light traveled in waves, decided to use a different tri-color arrangement of colors than the one used by visual artists.
Thomas Young wanted to "mix" colors back into white light. Because R + Y + B colors mixes into dark grey, he selected R + G + B as his mixtures. No scientist has yet to demonstrate that R + G + B light frequencies can be mixed into white light. Thomas Young piled on to his hypothesis the notion that human eyes only have photo receptors for colors in his favorite three hues: R + G + B. That notion has endured since 1802. The best part is Young’s declaration that humans only have capacity to receive certain colors frequencies so our brains have to mix mix colors into the other three hues? The theory is not natural and really confusing.
“Additive” R + G + B and “subtractive” R + Y + B color systems are obsolete concepts.
Going forward - in place of “additive,” use TRANSMITTED LIGHT, white light streaming through the universe. Humans eyes are receivers which can refracted white light into various wavelengths we recognize as colors. Colors maintain high intensity until they are reflected off skin, fabric (canvas) and stone.
In place of “subtractive,” use REFLECTED LIGHT. When white light hits an opaque surface, some color frequencies are absorbed. The colors not absorbed are REFLECTED back to human eyes. Whether receiving transmitted or reflected light, the process of seeing is the same. The difference is the quality of colors.
Reflected colors have value - relative brightness and darkness. Approximately half the natural light we see is grey because we see a combination of transmitted and reflected light. Artists (including the Impressionists) recognize this and use paints in all media including white and black colors to manage reflection and tonality. During the 20th century, art shifted toward abstraction which can rely on color without the dimensional quality of line and graphic image. Paintings, in general, have flattened and value is often obliterated. Through history the quest continues to be for brighter colors.
Human beings have been brightening up surfaces for at least 100,00 years. Masters manipulators of reflected light, humans probably started coloring skin before wood and stone. Archeologists have revealed human burial sites from the Neanderthal people who buried their deal in pits of red oxide pigments, the blood of the earth. Also iron oxide continues to be a popular colorant henna tattooing.
The colors of ancient cultures were made from natural mixed metal oxides. The color reflected back is created by the changing vibrations of light energy charging through the pigment structures which are crystalline. Whether applied to cloth or walls or boats, paints and dyes change the color reflected off surfaces and mark the property for identification. I can recognize my boat because is yellow when transmitted light enters into a varnish/oil transparent binder slows down in the viscous media and changes its angle of entry (refraction).
Different frequencies move through media at different speeds so the angle of refraction (degree of bending) is different for different colors. As the frequencies bounces back, some become diffused, but mostly we see “reflected” color frequencies.
Colorants manufactured today are made to be color at its maximum but often not the colors available to artists creating in digital media. The challenge is for those who master in digital media (transmitted light) is to “translate” their colors choices into colorants, pigments and dyes of reflected light. That can be done easily by adding more white and black colors to their palettes.
Tint - color + white (lightness)
Tone - color + black (darkness)
Shade - color + black + white
While I am debunking obsolete concepts from color science, a final one for this essay. Among the most frequently asked questions I heard during my career as paint manufacturer was: How do you define “warm” and “cool” colors?
Both artistic and scientific literature are littered with color systems based on a limited palette of colors. Based on a full spectrum array, the easiest answer is the oldest. Sir Issac Newton established two primary hues: blue and yellow. When looking at a color, if you see more blue, the color is considered “cool” and if you see more yellow the color is “warm.”
Because most oil paintings are made with a lot of white, consider adjusting the color of the painting white first especially in natural light situations. Adding a tad of blue, adds coolness. Adding a tad of yellow, adds warmth.