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Marc Crunelle: Teaching color to architects

Finally, we begin this series on Color Education!

Beware, in the world of colors, terms can have different meanings; the book “Colour, a guide to colour and colour mixing” by Royal Talens already warned us. But, although most authors define the terms they use, you will still need some mental gymnastics to adopt their own point of view.

The final version of these articles is the result of discussions with the authors — at least when they are willing to engage in this four-handed exercise — but it does not reflect my approach; the latter will be presented at the end of the series.

To inaugurate this collection of articles, I hand over the keyboard to Marc Crunelle.

Marc Crunelle (born 1949) is an architect, sculptor and doctor of spatial psychology.

If Amélie Poulain’s friend photographs a garden gnome in front of remarkable buildings, Marc Crunelle places a square of yellow fabric — like an ephemeral offering — at the feet of illustrious constructions and takes a photo of the scene. This ritual reflects his taste for travel, architecture, perception of space, and of course, color.

Yellow squares; photographs from around the world © Marc Crunelle

Here he gives us an introduction to the course he gave at the Horta-La Cambre Faculty of Architecture in Brussels. The title of the course? Visual and non-visual perceptions of architectural space.

After these architectural students, the decorative designers of the Royal Academy of Fine Arts in Brussels, the design students of the University of Nîmes, those of the Ecole des Mines de Saint-Étienne, and even the members of the Belgacom Communication Team, it is now your turn to benefit from his teaching. Or at least, to get an overview!

The objective of the course

The aim of the course was to present some aspects of the colored world from a perceptive point of view. The approach was therefore different from the study of physical theories, normative classifications, calibration, colorimetry, etc. In other words, the course dealt with the phenomenal aspects that we could experiment everyday by exploring current practices and applications such as advertising, fashion, etc.

This course consisted of two parts. The first part was a lecture as described below. The second part was an exercise: students had to illustrate Itten’s seven color contrasts on 10 x 10 cm squares ; they could find examples in magazines or produce the respective contrast by collage.

The subtitle of this course was: “The theory of color contrasts – Itten and after”.


Colors are deceptive, so three people will guide us through this world full of surprises: a chemist, Chevreul, and two painters, Johannes Itten and Josef Albers.

Before we follow them, here are some questions and definitions.

What do you think is correct in the following statements?

  • the rose is red,
  • for a color-blind person, the rose is purple,
  • in blue light, the rose is black.

Answer: All three are correct.

Indeed, what we call color is the interaction between 3 factors: a colored surface, a human eye and white light. So, to be more precise, we should say:

  • in white light, a rose looks red to a normal eye,
  • to a color-blind person, in white light, a rose looks purple,
  • in blue light, a rose appears black to a normal eye.

We can also say that colors are our interpretation of different wavelengths of light, or color is the way our eyes interpret the energy of light waves.

How are colors produced?

  • by matter: pigments (e.g. red gouache)
  • by light (e.g. traffic lights)

Some definitions

In this course, we consider these six colors as fundamental: blue, red, yellow, green, white and black. In addition, a specific shade is called a “tone”, such as peach, salmon or lilac.

To characterize the appearance of a color three factors were proposed by the American painter Munsell at the beginning of the 20th century:

  • Hue concerns what is commonly called “the color”
  • Saturation or chroma concerns the degree of coloring and measures the proportion of “pure” color in relation to white
  • Clarity or value or luminosity concerns the quantity of light transmitted by the surface and is expressed by adjectives such as “light” or “dark” (value in English)

At the age of 84, Matisse declared, “It’s all in the value, isn’t it? For one value on the right that wasn’t in place, everything in my painting went to hell. It doesn’t look like anything, a value… It took years to realize such a truth. And yet it is obvious (I add: to those who know)”.

The value of a color is a difficult concept to acquire; it is its clarity, independently of its hue and saturation; it plays a great role in the balance of a painting; it is what the painter controls when he blinks his eyes to probe his work.

How do we deal with the world of color (matter)?

Painters and dyers mainly investigated this field: they were concerned with making the color they used or made as beautiful and as present as possible. Let’s follow them!

First guide: Chevreul

French chemist in charge of the Royal Gobelins factory, Chevreul had to solve a problem: some blacks “did not look well”. After research, he concluded that the cause was not physical nor chemical, but optical: it was not the pigments that were at fault, but the colored tones in the vicinity.

Moreover, he wanted to rationalize the excessive number of shades used in tapestries. For some shades, it was quite difficult, if not impossible, to distinguish. He had noticed that the workers used their own method: to distinguish between two very similar shades, they put them next to each another.

On the basis of these observations he wrote his theory of color interaction: “On the law of simultaneous color contrast and the matching of colored objects”. A scan of the original text (in French) is available here. There he shows that a color gives a complementary shade in tone to a neighboring color: the complements illuminate each other and non-complementary colors appear “dirty”, as when a yellow placed next to a green takes on a violet shade (source: Wikipedia).

In short: a tone never exists by itself, it is always in a context and this context influences it.

Second guide: Josef Albers

Throughout his teaching and painting practice, Albers showed, in the continuity of Chevreul’s research, how deceptive color can be. Look at the yellow squares below. Against different backgrounds they all appear slightly different to us, even though they are similar, which shows that the “background” has an influence on this surface.

6 yellow squares on different backgrounds all appear slightly different to us
The same 6 squares on a plain black background.

A color is never alone, it is therefore influenced by its context, and the latter modifies its appearance to our eyes.

Albers has also shown in many paintings with the composition and patterns of 4 overlapping squares, that, depending on the distance to the painting, flat areas appear as gradations, that some tones “advance” and others retreat, etc.

His purpose is, as he says: “to learn to see”.

Josef Albers, two “tributes to the square” (source: Wikiart)

Third guide: Johaness Itten

It is with this painter that we will find explicit arguments about color and its multiple “behaviors”, based on the course he gave at the Bauhaus (Itten, “The Art of Color”).

His theory on color contrasts is based on a long tradition of color practice, not only in his own work but in the work of painters of all periods.

As he explains, his “theory was born of the painter’s experience and intuition. For the artist, the effect of colors is decisive, not the reality of colors, as studied by physicists and chemists. The effect of colors is controlled by intuition.” (p. 11) Note that in this article page number after the quotes refers to the French edition of the book.

Although he considers that intuition in the choice of colors remains a priority, some principles are useful in practice. “Extensive studies among the great masters of color have given me the firm conviction that they all possessed a science of color. Why should we name the principles that all artists should know and should have been taught to all of them as secrets?” he wonders (p. 12). To explain it, he quotes Charles Blanc the elements of the teaching of the colors were neither analyzed nor taught in our workshops of art, because one holds for useless in France to study the laws of the color, according to the proverb: one can become draftsman, one is born colorist.” (p. 12)

The chromatic circle of Itten

Itten’s color wheel is divided into 12 parts organized around a triangle of three colors that Itten defines as the three pure primary colors; then triangles of colors called secondary, each being a mixture of two primaries; finally on the outer ring, between the vertices of the hexagon, we find the tertiaries, mixtures of a primary color and a secondary. On this crown, two colors that are diametrically opposed are called complementary.

This circle to which is added the black and white is the basis of the contrasts considered by Itten.

Itten’s chromatic circle (source Wiki commons) (“Art of color” p.35).

Theory of colored contrasts:

The world around us presents a multitude of juxtaposed colors. The eye is attracted by certain colored encounters, by happy combination of tones that we call color scheme, as well as by violent contrasts. Of all these meetings, of all these contrasts, some seemed more relevant than others. The painters, concerned that the color they use renders their intentions well, have always favored some of these relevant encounters that they called contrasts.

Some have proposed 10 relevant contrasts, Johannes Itten has proposed 7: these are the ones on which we will base our presentation, and then we show how to go beyond this conception.

In his book, “Art of color”, Johannes Itten specified 7 contrasts that he defined as follows: “When, between two color effects to be compared, we can establish differences or significant intervals. When these differences reach a maximum, we speak of contrasts of opposition or polar. Thus, the terms large-small, black-white, hot-cold at their highest point are polar contrasts. Our sense organs can only perceive through comparisons.

When we look for characteristic modes of action of colors, we can establish seven different contrast effects.“(p. 36)

1. The contrast of the color per se

Yellow, red, blue express most strongly the contrast of color per se. To represent this, you need at least three colors that are clearly different from each other. The effect is always variegated, garish, powerful and sharp. The strength of the contrast effect of the color itself decreases as the colors used deviate from the three primary colors.” (p. 36).

Contrast of the color itself: on the left plastic lockers, on the right car tail lights.

If this encounter is sometimes fortuitous, as in the case of the plastic lockers or the rear lights of the car above, we quickly noticed its ability to attract the eye. It is also used in the design of informative or warning signs, as below. Moreover, it is a contrast that advertising uses widely.

Color contrast per se: warning and informational signs
Contrast of the color per se exploited by advertising

In addition, Itten points out that the farther away you get from pure primary colors, the less relevant the effect becomes. Look at the three images below to see for yourself.

The contrast of the color per se is less powerful when we move away from pure primary colors
2. The light-dark contrast

Light and darkness, light and dark, are for human life and all nature, of great and fundamental importance. Black, white and all grays. One accentuates the other. For example, the bell tower of dark blue slates appears blacker than it does in the clear sky.

Light-dark contrast: light colors on a dark background always stand out clearly. Bottom right: the photographer, who had to show a yellow jacket, chose a dark background.
3. The warm-cold contrast

This is how Itten defines the hot and cold poles:

Blue-green opposed to red-orange, cold and warm poles. A color can be sometimes warm, sometimes cold according to its contrast with warmer or colder tones.” (p.64)

Some situations can present several contrasts simultaneously.

Hot-cold contrast; right: Somville’s fresco at the Brussels subway station Hankar.
4. The contrast of complementary

Two pigmentary colors which mixed, give a gray-black, we indicate them by complementary. They are opposed, they require each other, they are strengthened to the greatest brightness next to each other. Yellow-violet, orange-blue and red-green are examples of complementary color pairs.” (p.78)

Furthermore, these colors are at their brightest when they meet their exact opposite (yellow-purple, blue-orange, green-red), as shown in the photographs below.

Contrast of the complementary colors. On the left: as a reminder, the color wheel according to Itten: the 3 primary colors in the center, then the mixture of 2 primary colors: yellow and blue gives the green, yellow and red the orange and blue red, the purple. In the middle and on the right: two examples of yellow-violet contrast.
Complementary orange-blue contrast, much more common.

One feels that there are better “combinations”, greater oppositions than others; it is besides one of the concerns of the painters: “a marriage of two complementary colors, their mixture and their oppositions, the mysterious vibrations of the brought closer tones” writes Van Gogh who used them widely. (Van Gogh, “letters to his brother Theo”, letter n°531, published by Gallimard).

It is also for the effectiveness of this contrast that the life jackets are orange: they are more easily spotted at sea.

As for the contrast of complementary green-red, when the complementary colors are the exact opposite, there is a vibration at the fringe of the two (see below).

Complementary green-red contrast producing a vibration at the limit of the two colors.

Taking into account a given element (the green grass or the red brick) and finding its complement allows to mutually enhance the colors.

Complementary green-red contrast; on the left, a park in Lille; on the right, the Belgian embassy in New Delhi (Satish Gujral architect)
5. The simultaneous contrast

By this we mean the phenomenon that our eye, for a given color, requires at the same time, therefore simultaneously, the complementary color, and that it generates itself if it is not given. The complementary color is generated in the eye of the spectator in the form of colored impression and it does not really exist. It cannot be photographed.”

Simultaneous contrast

A color “asks for” its complementary; the grays in the two pairs above, although identical, are slightly tinted with the complementary color of the one in the background. This subtle phenomenon can also be seen in the photo above: the gray letters appear slightly greenish. This phenomenon is more easily observed on a gradient background.

The following experiment allows to realize it differently: fix the red point below for about thirty seconds, then look at the white surface to its right; for a short time you will see the ghost image of this point in green. This contrast is also called successive contrast.

Successive contrast: stare at the red dot on the left image for 30 seconds and then move your gaze to the right, on the cross.

An interesting application of this contrast can be found in operating rooms. Before, surgeons would bend over a red wound in the middle of a brightly lit white sheet; when they looked up to ask an assistant for a tool, the ghostly image of the wound would appear in green on their white clothes. To avoid this disturbing appearance, the surgeons’ clothes are now green or blue-green. In addition, the red color (of the wound) being the complementary of the green, it is better distinguished, which facilitates their work.

6. Quality contrast

We understand the concept of quality of color, the degree of purity or saturation of colors. We designate by contrast of quality the opposition of saturated, luminous colors and colors extinguished, dull. The colors of the prism, which are born from the refraction of the white light, are colors of the greatest saturation or luminosity.

It is in the art of confronting them that all the richness of this contrast is found. Below, the bands of red solids become gradients. In Raphael’s painting “Pope Leo X with two cardinals”, there are pinks, vermilion, browns, burgundy, a set of reds and yet, the whole is not messy, all the visibility is kept, just like in the illustrations that follow.

Quality contrast

You can play on the nuances of the same tone range without losing character.

Quality contrast in the purple-blue: top left: denim jacket sandwiched between two purples; top right: a dark blue tablecloth blends perfectly with blue chairs and a gray floor. Below, on the left, the different blues remain autonomous; on the right, the walls, the base, the central door and the sky are in a range of blues while a warm (and complementary) color indicates the access doors.
Contrast of quality and architecture: on the left, an orange-yellow door on an ocher background; on the right: which color to choose in an environment given by a red wall located on the left, black frames and roof, and white sunshade tents? The architect selected a Naples yellow for all the masonry.
Quality contrast and legibility: with a set of shades of green enhanced by a little yellow, we can have compositions with character and visibility.
7. The contrast of quantity

“It concerns the ratio of sizes of two or more spots of color. It is thus the opposition “much-little” or “large-small”. The colors can be composed with each other by spots of variable size at will. But we must ask ourselves what is the ratio of size between two or more colors that we can say is balanced, and that none of the colors used has more importance than the other. Two factors determine the strength of the effect of a color: the brightness and the size of the spot.

To assess the strength of radiation or brightness, which is called the light value of a color, we must compare the pure colors on a neutral gray background of average clarity. It will be established that the intensities of effects or light values of the various colors are different. Goethe had indicated for these luminous values the simplest numerical reports and for us the most usable. These figures are approximate values.

The values of light of Goethe are: yellow: 9 / orange: 8 / red: 6 / violet: 3 / blue: 4 / green: 6,

The values of the complementary couples are:

yellow-violet: 9-3 or 3-1 or 3/4-1/4 ;
orange-blue: 8-4 or 2-1 or 2/3-1/3
red-green: 6-6 or 1-1 or 1/2-1/2

If one transforms these values of light into sizes of luminous spots, it is necessary to use reciprocally the figures of value of light. The yellow of strength three must therefore occupy an area three times smaller than the complementary violet.” (p.104)

Contrast of quantity; on the left: proportioning of the colors according to the values stated above; on the right: mural composition of Miro in the airport of Barcelona; it respects the balanced proportions proposed by Goethe: 3 times more blue surfaces for one of yellow, and surfaces of equal amplitude for the green and red.

The colored contrasts, after Itten

Let’s remember that Johannes Itten is an artist of the mid-twentieth century.

On the one hand, his theory of contrasts is a painter’s proposal; other painters have formulated different proposals. Thus, we can state some other contrasts, such as the contrast of color-non-color, the blue-red contrast, the consideration of golds and silvers, etc.

And on the other hand, the industry has developed colors that did not exist in Itten’s time, such as fluorescent paints.

Effects just as relevant as those presented above exist and occur daily.

1. The color-non color contrast

A color associated with a gray can have a certain character, even be more vibrant.

Color non-color contrast
2. The use of gold and silver

This contrast of a traditional color juxtaposed with gold or silver was widely used in Byzantine icons, medieval paintings and illuminations; in these works, gold symbolized light. Gustav Klimt also used it brilliantly in his work.

Contrast making use of gold
3. The blue-red contrast

The opposition of these two colors sometimes creates a vibration that we find in the stained glass windows of Chartres, and which continues to fascinate us.

Blue-red contrast; top: examples in the communication; bottom: stained glass windows of Chartres cathedral (source wiki commons)
4. Fluorescent colors

Invented after Itten, fluorescent pigments are widely used nowadays (the brand Day-Glo markets them since 1950). They are used to color tennis balls, but also clothing requiring high visibility.

On a daily basis, we notice that they are widely used for their bright appeal.

Fluorescent contrast
5. The yellow-black contrast

We noticed that the greatest disparity between 2 colors was between yellow and black. This characteristic is used in the signage of airports, including Zaventem.

Yellow-black contrast used in the signage at Zaventem airport

Thanks to the guides!

Color can have a powerful impact in many situations, and when put in the right conditions, it is enhanced to its greatest intensity.

With these few guides, you can save a lot of time in your work but also grasp in a much more comprehensive way the work of many painters from all times.

The light colors

So far, we have considered subtractive synthesis; it is called subtractive because we start from white by successively removing the emitted rays perceptible to the eye, through colors placed on surfaces; if we remove all the rays, we obtain black. The subtractive synthesis operates in our daily life, at the level of the “colors-matter” that we handle or observe every day, as the illustrations presented above showed it.

The additive synthesis (where one adds successively the lights, for example blue, red and green to arrive at the production of the white) is that of the lights, those emitted in particular by the screens of television and computers.

Let us conclude this article with two relevant applications of colored lights.

Butchers use hot-light TL to illuminate meat and make it appear more rare. In contrast, halal butcher shops use cool lights to present a less red meat.

Blue lighting is sometimes found in the toilets of bus stations, railroads, or even in dance halls. The reason for this is that the veins do not show up well in blue light, so junckies will not prick themselves in these places.

Let’s leave the last word to another painter: Kandinsky: “the eye feels the color. It feels its properties, it is charmed by its beauty. The joy penetrates the soul of the spectator who tastes it like a gourmet a delicacy.” (“Concerning the Spiritual in Art”).

To go further

Here are some readings that I recommend:

Sean Adams, “The Designer’s Guide of Color”, Abrams Book, 2017.

Josef Albers, “The Interaction of Colors, 50th anniversary edition”, Yale University, 2013.

Manilio Brusatin, “History of colors”, ‎ Shambhala, 1991.

Johannes Itten, “The Art of color”, Reinhold Pub. Corp; First Edition Fifth Printing (January 1, 1969).

Other books in French are suggested here.

Note: Illustrations

With the exception of the Alber’s and the Raphael’s paintings and the Chartres stained glass window which are in the public domain (Wikimedia Commons), all illustrations are from Marc Crunelle.

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