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16 Lessons in Color Theory

Lesson #11

I know that these two lessons are coming quite close together but they fit with each other and I want you to have this information for your records.


The following descriptions are valid for colors in any medium; exceptions are clearly stated. The descriptions are in a sequence recommended for arranging the colors on your palette: reds, oranges, yellows, blues, violet, greens, browns, blacks, and whites. Please note that all qualities refer to colors made by respectable manufacturers of artists' colors.


Alizarin crimson: a bluish red of low brilliance, very transparent, darker than the deepest cadmium red. Alizarin crimson is excellent for glazing in any medium. In aquarelle, thin it with water; in casein and polymer, add as much water as you wish, but add also a drop of casein or polymer medium, respectively, so that the paint won't lose its adhering power. In oils, mix alizarin crimson with linseed oil or copal glazing medium. Washed or glazed over any color, it lends depth and pulls large parts of a painting together, without obliterating details.

If, in any part of your painting, you want alizarin crimson to look like itself, apply it directly on the clean, white support. In case of mistakes - and we all make them, you know - wipe or scrape off the wrong color before applying alizarin crimson. In casein and polymer, cover the mistake with titanium white, let it dry, then paint alizarin crimson over the white. Alizarin crimson is a must for every kind of representational painting, and desirable in nonobjective works as well. Remember, the slightest admixture of white changes the hue RADICALLY!

Geranium Lake: a very bright red, excellent in transparent watercolor, but not used in other media.

Rose madder: a little closer to red-violet, is another transparent color extensively used by aquarellists, especially for cool reddish washes.

Cadmium red medium: the most practical of the vermilion-type reds. Made of the metallic element of the same name, it's a yellowish red of medium brilliance, absolutely permanent, opaque, with great covering power. You can paint cadmium colors over any other color, even in aquarelle. Cadmium red glazed with alizarin crimson becomes darker, but cadmium completely covers alizarin. Cadmium red deep is not as bright as the medium red, but may be useful in aquarelle.


Cadmium orange: a very important color, even though, theoretically, it can be mixed from cadmium yellow and red. You must have the ready-made orange for purity, and intensity. It's very valuable in all mixtures where a warm, but bright tone is desired.


Cadmium yellow light and medium: both are needed, because you cannot obtain a brilliant pale or lemon yellow by adding white to the medium yellow. On the other hand, any addition of a darker hue to yellow males it a different color. Be careful not to add too much cadmium yellow to any other color, as it is extraordinarily powerful.

Yellow ocher: one of the most important earth colors, is of medium opacity. Mixed with a drop of white and/or cadmium yellow, it has a good covering capacity. Applied in washes, or glazes, it's another excellent color for pulling together sections of a painting. For example, you can paint a moonlit, or gaslit scene in detail, then go over the picture with an ocher glaze of the required strength to unify the tones.

Gamboge or Indian yellow: a slightly greenish, or dusty yellow of great subtlety. It's truly transparent; so much so that it is used almost exclusively in aquarelle.


Ultramarine blue: one of the oldest blues, and still one of those without which no painter wants to be caught. It's called ultramarine, that is, "from beyond the sea," because it was produced from lapis lazuli imported to Europe from Asia. That was hardly an overseas import; most of the lapis lazuli must have been transported overland by caravans, rather than by ships; but it did come from the mysterious East, and was expensive.

It has to be pulverized, and carefully separated into lighter and darker shades. Despite its darkness and visual power, ultramarine blue is a transparent color. A modern variation of it is called French ultramarine, a warm blue. mixed with a little white, this hue has a slightly violet tint, which is especially noticeable when placed next to cobalt blue and next to cobalt blue mixed with white.

Cobalt blue: made from the lustrous, somewhat magnetic metal of the same name, often mentioned in connection with atomic power, and cancer research, is absolutely permanent, semi-opaque. fine for skies, lakes, and all mixtures in which coolness is desirable. Like other metallic hues, it's more expensive than earth colors, but no pictorial artist can work without it.

Phthalo (Phthalocyanine) blue: a recent discovery (in relative terms), is similar to Prussian blue, without its overwhelming and dangerous strength. It gives brilliant sky tones, and turns warm colors cool. Transparent, ideal for glazing where an overall cool bluish tint is required.

Other blue colors have been, and still are available. Indigo, one of Sir Isaac Newton's seven prismatic hues, was made from several plants. It's now produced synthetically, is more uniform in quality, and more permanent than the natural dye, but isn't recommended for fine arts painting. The same color can be obtained by adding a drop of black to ultramarine blue.

Prussian blue: an iron-cyanide compound, discovered in 1710 by a German named Diesbach. It's a deep blue pigment with a coppery luster. A beautiful blue, especially when mixed with white, but so powerful that it "kills" every color with which you mix it, even though it's transparent. Like asphaltum, it rises to the surface, gradually, and where you intended to have a slight Prussian blue tone, you find a dark blue spot, completely out of harmony with the rest of the picture. I strongly advise you against employing Prussian blue.


Cobalt violet: a lovely, opaque hue, much cleaner than if you mixed it yourself, although cobalt or phthalo blue with alizarin crimson and a little white ought to provide you with a nice enough violet. Ready-made violet can easily be turned darker and warmer by adding alizarin crimson; lighter and cooler, by adding cobalt blue and a dash of white. Never add cadmium red, because it turns blue into maroon, rather than violet.

Since violet is a sort of in-between hue - not too warm and not too cool - it goes well with almost anything. An earlier generation of students heard art teachers say: "When in doubt, use violet." The advice is still good, but don't overdo the use of violet. mixed with white, violet should always be applied with a perfectly clean brush and a very clean liquid, whether oil, turpentine, or water. This, by the way, is true for all sensitive pastel shades, because the smallest bit of extraneous color destroys their delicate tones.


Phthalo green: similar to the blue of the same name, a cool green of great intensity when mixed with a little white and light yellow. Like the blue, it's transparent, but quite opaque and powerful when white is added. On a hot day, I'd like to sit in a room painted a pastel shade of phthalo green! It's excellent for foliage in the distance. Also, for the cool, pale green sky of a radiant sunset.

Chromium oxide green: a warmer green, semi-transparent. A fine middle-tone for foliage, and other vegetation. Turn this color warmer by adding orange or burnt sienna, cooler by adding cobalt blue and/or white.

Hooker's green: transparent, used in watercolor and polymer, especially for outdoor painting, when a large variety of green shades is required. Hooker's green differs in mixtures from other greens sufficiently to make it worth your while to have it.

Viridian green: also transparent, is liked by many artists, but I use it only in watercolor and, occasionally, in casein. I find it superfluous in other media, because I can obtain all imaginable green shades by mixing phthalo green and chromium oxide green with various blues, yellows, white, burnt sienna, and literally any other hue.


Burnt sienna: one of the most widely used earth colors, actually a member of the family of ochers - pigments varying from yellow to red - found in many parts of the world; derives its name from the Italian town of Siena, where it was first used as a color. It is often called Terra di Siena - earth of Siena - with a single "n", the Italian spelling. In its original form, raw sienna is a cool, grayish brown. When burnt, calcinated, it turns into a mahogany brown, good for warm shadows on the human figure.

Many portrait painters lay their work out in burnt sienna tones and go over these with the actual flesh colors. A burnt sienna underpainting is less dangerous than the black-and-white underpainting Leonardo da Vinci did for his Mona Lisa, in which the black had bled through, especially in the shadow under the chin, causing it to look almost black. Only the lovely hands have retained their full flesh tones. Leonardo probably used better pigments in that part of the painting, or went over the underpainting with more glazes than he did the face and chest.

Burnt sienna mixes well with many colors, although too much of it in face or figure causes it to look kind of bloody. Both raw and burnt sienna are transparent. I find raw sienna superfluous, because I can obtain the same hue by adding a little blue or black to burnt sienna.

Raw umber and burnt umber: two other earth colors highly favored by many artists. The pigment originally comes from the Italian region of Umbria, but the word ombra happens to mean shadow in Italian, and some people think that's the meaning of the color, because it's good for certain shadows. I don't recommend either of the umbers, because I find them too strong. Everything mixed with burnt umber looks like something made of, or covered with, chocolate sauce! You can obtain the same color by simply adding black, blue, or green to burnt, or raw sienna.


Payne's gray: a pleasant, transparent, dark gray, available in most media, and favored by artists who are prejudiced against black. It's very handy in aquarelle when you want to make other colors slightly darker, especially in the form of an over-all wash.

Needless to say, grays of any shade can be obtained by adding more or less black to white, and modifying them with the addition of a touch of red, blue, green, or any other hue.


Ivory black: sounds odd, doesn't it? Ivory is anything but black. The reason for the name is that this color is made of bone carbon, not necessarily from elephant tusk. It's transparent, so that it can be used as a wash or glaze when sufficiently diluted. It's a cool black which mixes well with any color you'd like to tone down to what we call a "dusty" shade.

Now I am aware of what purists say about black not being a color, and I know that in previous lessons I have counseled you to be cautious about using it. I suspect that some artists avoid black because the improper use of it can create "mud" in your painting. However, at this stage of our studies we ought to be accomplished artists with a keen awareness of how to handle our colors.

Lamp black: a warmer black of very light specific gravity, and not much covering power. Add a touch of burnt sienna to ivory black, and you have the identical black hue, but you obtain a considerably stronger paint. In transparent watercolor though, lamp black is useful, because the specific gravity of a color is immaterial in the medium. I don't recommend it in any other kind of painting.

Mars black: the best available black in polymer. It looks just like ivory black. It's prepared from synthetic, uniform, fully permanent oxides.


Flake white: until shortly before World War II, this was the favorite in oils; many old timers still stick to it as a matter of habit. Made of lead, it's opaque and smooth, with excellent covering capacity.

Zinc white: made of the metallic element of the same name, zinc white is harmless and stays pure white. It is, however, so transparent, so weak in covering power, that you need a great deal of it to make a color lighter. It also dries more slowly than most other paints, and this is a handicap in oil painting, where uniform drying time is a safeguard against cracking. In the past, technically well-informed and conscientious artists worked with flake white, but covered sections, the whiteness of which was essential, with zinc white, after they dried. The slower-drying zinc white did not effect the faster-drying, or already dry colors on which it was applied.

In some cases, the yellowing or darkening of white sections in an oil painting may be of no importance. It may even lend the painting a kind of softness by eliminating harsh contrasts. As a rule, though, an artist likes his colors to remain unchanged.

Titanium white: the most recent discovery, fills the need for a new white. Made of titanium - the metal employed in producing light, but extra strong steel for aircraft - this is the most powerful as well as most permanent white known today. Painters accustomed to flake or zinc white have to adjust themselves to this stronger white.

For many non-purist aquarellists, and the innumerable commercial artists who need retouching white, I advise you to buy the finest white, nothing but what is guaranteed to remain white. Such whites come in tubes or small jars, and may be diluted with a drop or two of water. You can verify the permanence by applying a few strokes on a piece of cardboard and exposing the card to sunlight for a few days. Cover half of the strokes with another card, so as to be able to compare the change, if any. The so-called Chinese white is usually the best.

So there you have it. I hope that this will help you to understand what your colors will do for you. In the next lesson we move on into the mixing process and I also want to talk a bit about things like gels, modeling pastes, extenders, and textures. See you soon.