Overview
This 36 pages booklet edited by Royal Talens, very practical, gives the rudiments of color theory and explains how to use them in painting. The book is divided into 4 chapters: (I) the formation of color, (II) the color properties, (III) the mixing of colors, and (IV) the use of color in painting. The illustrations, simple and numerous, are very educational. The booklet is partially available in English here and in several languages there.
Please find below a detailed summary followed by my own opinion. Note that I do not have any financial interest in promoting this guide.
Detailed Summary
For obvious copyright issues, there is no illustration in this article.
The origin of color
The first chapter introduces the notion of spectrum, which is fundamental to the understanding of color. In fact, a colored substance reflects all the rays of the solar spectrum in different proportions (rarely zero), and it is this relative proportion that determines the perceived color. A pure color is defined as one of the colors of the rainbow, so that white, black and grey, which are absent from the rainbow, would “theoretically” not be colors.
It then then introduced dyes and pigments, which are distinguished in particular by their resistance to light – to the disadvantage of dyes, whose use should therefore be limited to temporary work. The properties of pigments, namely (1) lightfastness, (2) hiding power and (3) intensity (i.e. tinting strength) are explained and their representation on commercial labels is given; the finer the pigments are ground, the more intense the color.
Properties of colors
The second chapter presents the following color properties: temperature, hue, brightness and saturation. The authors note that these same terms may have different meanings in other publications.
The temperature is translated by the qualifier hot/cold which corresponds to the impression of warmth that one would have in a room of this color. The relative aspect of this property is emphasized: a green may seem cold compared to a yellow and warm compared to a blue; within the visible spectrum, blue is proposed as the center of the cold area while orange-yellow the center of the warm one.
The notions of hue and saturation are explained by the relative proportions of the reflections of the solar spectrum. The greater the ratio, the more dominant the color is. Saturation, on the other hand, is associated with the degree of purity of that color. The less pure colors, i.e. black, grey, white are said to be unsaturated or polluted.
The brightness of a color is equated with its clarity, in other words, the proportion of light it reflects. A color mixed with a grey of the same brightness will retain its brilliance but will lose its saturation.
Mixing colors
The third chapter presents the mixing of colors made from paints. As each colored substance absorbs part of the spectrum, by mixing them, more of it will be removed. This is known as subtractive mixing, as opposed to the mixing of colored light, which, as the spectra are added, constitutes an additive mixture.
Two systems are then offered, starting with three and six colors.
In the first system, the primary colors: lemon yellow, cyan (blue) and magenta (red) are defined as such because, on the one hand, by mixing, they can produce any shade including black, and on the other hand, they cannot be obtained by mixing.
Two figures illustrate how, starting from these three primaries arranged equidistantly on a circle, six colors (yellow, orange: yellow + magenta, magenta, violet: magenta + cyan, cyan, green: cyan + yellow) and then twelve (mixing each of the neighbors again) can be produced. This operation could be repeated until the colors blend together.
Then, by mixing these colors with white and black, the number of possibilities is further expanded. Black can be dispensed with: by mixing one color with the opposite one on the circle, a very dark grey is obtained, each mixing color removing a different part of the spectrum so that hardly any part is finally reflected.
The colors that, when mixed together, give black are said to be complementary. The three colors produced by mixing the primaries are called secondary. The mixing of two neighboring secondaries on the circle results in a tertiary color.
The defect of the colors produced by this mixing system is their lack of saturation. This is why a system based on six colors is proposed: a blue plus purple (ultramarine) is added, another yellow plus orange, and a red (vermilion). These three colors take their place on the circle by replacing certain colors in the mixture of the three primaries.
Optical mixes are then discussed; pointillist and glaze mixes, classified in this category, are explained.
Pointillist mixing consists of creating a color by juxtaposing spots or dots, for example a surface covered with yellow and blue dots will give the impression of being green. Juxtapositions of complementary colors will give a less saturated color by optical mixing. White, black and grey dots will also influence the resulting brightness and saturation of the optical mixture. The dots can be applied to a colored or white surface, the resulting optical mixture will be more or less saturated.
Mixing by superimposing layers of transparent paints is called glazing. For best results the guide recommends overlaying darker and darker colors. This technique is not suitable for gouache because of its opacity.
Painting with colors
The final chapter explains how to use color properties in painting for depth and realism.
From the observation of a photo of a landscape of fir trees in the mountains, the impression of depth is analyzed; it results on the one hand from the change in size of the same objects (i.e. the fir trees) according to the different planes and on the other hand from a change in color.
Four planes are identified on the photo: the foreground with large fir trees, the second plane with fir trees behind a lake, the third plane with the mountain where the fir trees are still distinct, and the last plane with the mountain and the sky, where no objects are discernible.
Each plane is analyzed on the basis of a pair of colors from this plane: one representing the lightest colors, the other the darkest. The result is as follows: the greens in the foreground are warmer (i.e. yellow), and become cooler (i.e. blue) as successive plans are developed. This effect plays on both elements of the couple (i.e on the light and on the dark one). On the other hand, the further away you go, the more the contrast between the darker and lighter colors in the plan decreases and the more the color loses its saturation.
From this analysis they draw these three rules: (1) The color temperature cools down as the distance from this color increases (i.e. the color becomes colder). (2) A dark color always lightens as it moves away. (3) The saturation of a color decreases as the distance from it increases. At the zenith, however, the color of the sky is more saturated, so this rule only applies to the distance to the horizon.
Graphic illustrations show how these effects and these contrasts are used to create depth. The artist will combine these different effects and the variation in size and shape to produce the desired depth impression.
Finally, the improvement of the depth impression is illustrated on several examples: color temperature, saturation and local contrast not only enhances the depth but also the realism of the picture.
Appendix and Index
In the appendix you will find a list of the product numbers of the three primaries for oil, acrylic, watercolor, gouache, ecoline and decorfin for the different product ranges offered by Royal Talens. An index with most color terms is also provided.
Critical opinion
Overall rating: 4/5
This little guide is excellent for its conciseness, simplicity and educational illustrations. The terms used are well defined and the reader is warned that they are not universal. Its main shortcoming is to overlook the visual system, which is fundamental to the understanding of color. The weakest part of the booklet thus lies in the relation between the physics and the color properties (chapter I and II).
Beyond the questionable choice of vocabulary, a few small mistakes are present.
To define a “color”, even if it is called “pure”, as one of the colors of the rainbow, excludes not only black, white and grey, but also magenta, brown, pink and many others. The colors are not in the spectrum. Indeed color is a production of the mind: it is a complex judgement based on several factors: the source of light illuminating the colored surface, the reflected part of this source and probably, to a lesser extent, our culture.
To simplify, we can limit ourselves to treating the part of the solar spectrum reflected by the colored surface, but we cannot oversimplify by attributing to it a color which would be the mixture of colors associated with the rays of the solar spectrum. A monochromatic ray in itself has no color even though it can produce a colored sensation. Therefore, there is no such “pure color”.
Hue can be seen as the dominant color (i.e. it “dominates” in perception), but this does not mean that the monochromatic wave corresponding to this color dominates in the reflected spectrum as the guide claims; for example the spectrum reflected by a yellow lemon does not show a peak between 570 and 580 nm.
For those who are curious, several articles of this bog deal with color perception. Follow the tag #color_perception.