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Question & answer resource for artists.
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Color Page

Primary Colors
Standard Paint Colors
Color Theory
Lightening/Darkening
Colors for Beginer
Complementry Colors
Simultaneous Contrast
Improving fleshtones
Old Masters Look
Mass Tone & Undertone
ALSO:
My Color Mixing Page
My Color Theory Page
Color Theory Links



Why when I add white to my warm colors do they go cool?

Many warm colors have a cool undertone and you are probably using a cool white as well. Titanium White, now most commonly used in place of Lead White, is cool, whereas Zinc White which is often shunned for its bad reputation as an oil color is warmer. Some people, however, use Zinc as their mixing color as its lesser opacity to Titanium White is desirable when delicacy is called for. In anycase, the natural cooling effect of any white can be offset by a small addition of the next lightest warm color in the range. I prefer to just keep a warm white made with a touch of Yellow Ocher and a cool white made with a touch of blue (Cerulean Blue is a good light colored and weak tinting blue albeit not cheap) ready on the pallet giving me a choice to warm or cool when I lighten a color... warming a naturally cool color will not shift it to warm but rather just makes it more subdued.

    Warm White
    Cool White
Lightening with white is neccessarily de-saturating, so some people choose to lighten cool colors as well as warm colors by using an intrinsicaly light color found on the given scale... some people lighten violets, blues, and greens with Cerulean Blue but I can't imagine someone adding green to a blue inorder to lighten it. Some people also follow the practice of darkening colors with the next color down on their own scale to offset the de-saturation caused by adding a relatively neutral black.

I actually often use Burnt Umber and Raw Umber to darken warm colors and cool colors respectively rather than using black... on the other hand I still love the magic of mixing a subdued green from yellow and black.

    Raw Umber
    Burnt Umber
You could ask why darkening a yellow with the less saturated Yellow Ocher or even a Red would be preferable to just using black. The answer is simply that Yellow Ocher or a Red contain less of yellow's complement hue violet than does black and thus would de-saturate it less and also prevent it from turning greenish. Likewise, lightening a red with orange or yellow imparts less blue to it than adding white.

The key is using a mixture of lighter or darker color with white or black respectivly to keep the color temperature from shifting but without actually changing the essential hue of the color perceptibly... one wants to avoid the crude and naive look of simply shading a orange form, for instance, with a pure dark red. "Color consistancy" across areas of local color should not be disregarded merely for the sake of maintaining maximum saturation. Ultimately the brilliance of saturated colors is defeated if it is used uninterupted across a composition... this is the most common failure I see among student works.


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What is simultaneous contrast and how does it work?

Perhaps your best bet is reading Michel-Eugene Chevreul 's original treaties of 1839 De la loi du contraste simultane des couleurs. I have not read it my self but it is the seminal work in color theory. Chevreul, if I remember correctly, was a chemist brought in by a French industrialist to analyze why a tight weave of red and green fiber had turned out to give a dark gray color effect. He determined on an empirical rather than theoretical basis that so-called complementary colors mixed below the eye's ability to resolve will blend toward chromatic neutrality while is sufficiently large in are to be resolved will have the effect of augmenting each others chromatic intensity.

Since then, biological researchers have determined that there are 6 million color receptors (cones) in the retina of the eye and only 400,000 optical nerves communicating color experience from the eye and apparently there is a great deal of signal processing taking place in the retina before signals are passed ont oth the optic nerves as signals from these multitudes of cones converge on far fewer gaglion cells before going on to the thalmus and then the cerebreal cortex.

Among effects of retinal signal processing demonstrated is a contrast enhancing mechanism that is called simultaneous contrast or reciprocal contrast and is based on the inhibition of adjacent lateral zones of responce on the retina upon exposure to strong stimuli of a given value or hue. The result is a negative impression of the stimuli akin to an after image... this "chromatic": induction" exaggerates the value or hue contrasts in a scene enhancing edge detection and other perceptual processes further along the visual systems. In practice, a red figure on a white background may induce a slight green edge impression while a red figure on a green ground will crate an enhanced impression of redness in the figure induced by the background and an enhanced green impression in those parts of the background laterally adjacent to the red figure due to the previously mentioned green edging.

Although this phenominea might seem similar to "afterimage effects"e it actually has a quite distinct physical basis. In afterimage, strong exposure to a hue results in the momentary depletion of the retinal pigment (idiopsin) most responsive to the given stimuli... when that stimuli is replaced with a neutral field a negative impression of the original stimuli is experienced... surgeons ware green to mask potential green after-images caused by looking up from the red body cavity after intense focus. Simultaneous contrast however, is the result of cross stimulation of cones and ganglion nerves that inhibits stimuli impression in adjacent areas while consolidating it within the reception area... each nerve stimulating group of cones is typically encircled by a group of cones that give nuron activity suppresive signals in response to the same stimuli that causes the central group to give neuron excitory signals.

I would hazard to propose that this mechanism of consolodation and contrast might in part be responsible for color consistency in the case of perceived local color (although not in the case of successive or fluxing light environment) despite the fact that it is clearly responsible for both the so-called "value fluting effect" and "hue accomodation" effects.

See my web page on color mixing for specific hue complement pairs.


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What are complementry colors and why are they important?

I think every book I have ever read has simply stated that complementry colors are those colors found directly across from eachother on a color wheel .

This is descriptive rather explanatory.

Complementary colors are colors having hues that are composed of the additive primaries in inverse proportion to each other.

When complementary hues are mixed additively the result in a white sensation: for instance, a blue spotlight cast over a yellow spotlight will give an impression of white light... The red and green light constituting the yellow beam when added to the blue light of the blue beam give a balance of the additive primaries red, green, and blue that matches our sensation of neutral "white" sunlight.

Here is a graph of cone group response proportions to the range of spectral light frequencies.

The colors yellow and deep blue are complements because the blue is featured fully of blue light that does not cause any red or green retinal cone response where as the yellow light sensation is derived from the stimulation of red and green receptive retinal cones.

When complementary colors are mixed subtractively the light reflective properties of each constituent color is canceled out by the other causing a desaturation which in balanced mixing results in a completely achromatic gray of very low brightness.

Phthalo Blue                  Cadmium Red
Lemon Yellow                  Blue Violet
Rose Madder                                Phthalo Green
For example, when magenta pigment which absorbs green and reflects red and blue stimulating those cone sets is mixed with green pigment which absorbs both red an blue light and stimulates only green responsive cones are mixed the result is an absorption of light from all three frequencies bands to which the retina is sensitive. Because of this effect, complimentary pairs are useful in modifying each others hue saturation with less value shift than would be the case in using black or white to desaturate... A weak tinting green like terre verte can render vivid reds more subdued without noticeably lightening or darkening them making it an important color in portraiture.

See my color theory page for a more thorough discussion of color vision.


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What are the primary colors?



They really are Cyan, Yellow, and Magenta: known to us painters as turquoise blue such as cobalt or phthalo, lemon yellow, and a very cool bluish-red known variously as madder, crimson, carmine, rose, ultramarine violet, etc.

Rose Madder    
Lemon Yellow    
Phthalo Blue    

See my Color Mixing and Color Theory pages.


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What is color theory?

-- It is a number of related endeavors, the attempt to understand the physical, physiological, and neurological aspects of color vision. Often color specification, the attempt to describe and order color and color relationships using schema, regularized nomenclature and models such as so-called color solids is included under this term.

-- The widely supported view of color perception is currently a "step" hypothesis based on the Young-Helmhotz model of retinal photoreception and the Hering theory of oppositional neurological processing... in short, the eye has four sets of color receptors based on nerves that signal when the photo-reactive pigments attached to them break off in response to light... these pigment bonds are continually refreshed, although it is the lag time in this process that results in persistence of vision and so-called after images. The one set of receptors are called "rods" and respond only to low level light and give us our monochrome night-vision, the three other set are called "cones" and respond to low, medium, and high frequency photo-stimulus respectively... they are called either Rho, Gamma, and Beta cones or Red, Green and Blue cones. A complex of processing at the retina, in the thalamus, and in the cortex translate stimulus from these cone sets to extrapolate the subjective experience of color. The sets have peak response to vermilion, green, and deep blue-violet frequencies of light respectively... combinations of stimulation by these three light frequencies, so-called additive mixing, can effect the same color sensations as those created by any given individual frequency of spectral light plus the range of purples.


See my color theory page and my color mixing page.


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I am just starting out with painting, what colors should I buy?

All you need is the three primaries:

Rose Madder    
Lemon Yellow    
Phthalo Blue    
plus Titanium White

Most people use Titanium White which is strong and cool where as Zinc White is warm but is weak and has a reputation for making overly rigid films in oil. Some people call Zinc White, ":mixing white" since it is less apt to shift fleshtones cool or overwhelm other colors in mixing. Most people now avoid Lead White (a.k.a. Flake White and Blanc Argent) because of its highly toxic effects on ingestion and the fact that it is more apt to change or blacken due to environmental contamination such us the presence of sulfer in the air or other pigments.

The next three to add might be the secondaries:

    • Cadmium Red Light Hue (the word "Hue" indicates a cheaper sythetic stand in for the true Cadmium color)
    • Phthalocyanin Green
    • and a Deep Blue Violet (ultramarine or cobalt violet)
    • or Cerulean Blue, a light weak tinting greenish blue.

Cadmium Red Light    
Phthalo Green    
Cerulean Blue    

Three more useful colors are:

Yellow Ochre    
Phthalo Blue-Green    
Dioxazine Purple    

You could add these very usefull but very inexpensive earth colors that are important for fleshtones and hair in portraiture.:

  Raw Sienna       Raw Umber       Terre Verte    
  Burnt Sienna       Burnt Umber       Indian Red    

You could buy a black or mix it from the Magenta or Burnt Sienna and the Phthalo Blue or from Phthalo Blue and Raw Umber as I do. Bone Black is transparent and blueish, Mars Black is opaque and brownish, Ivory Black is a fine grade of Bone Black and Peach Black and Lamp Black are richer somewhat nuetral blacks.

In pigments I prefer the transparent synthetic azos to the expensive (and opaque) cadmium colors but I do have a preference for the various expensive cobalts over the cheaper but less subtle phthalocyanins and I prefer the quinacridone magentas/violets over the traditional anthraquinone alizarine crimson, because they have a nice mass tone (Alizarine looks almost black just out of the tube) and are easier to control in mixing.

See pigment color chart.


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How can I improve the fleshtones in my portraits?
1. Use those earth tones.

  Raw Sienna       Raw Umber       Terre Verte    
  Burnt Sienna       Burnt Umber       Indian Red    
Fair complexions can be mixed most easily from the red earths and the burnt and raw siennas added to white and dark complexions by adding yellows, reds, greens, and blacks to burnt or raw umber. Medium complexions can usually be developed straight out of yellow ocher, raw sienna or a lightened raw umber.

    

2. Think about whether a color is darkening or merely cooling on the receding planes.
3. Cool light and medium complexions using cerulean blue and/or terre verte since the are weak-tinting light cools.
4. Warm with glazes where the blood comes closest to the surface (the ears for instance).


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How do I get that "Old Masters" look in my paintings?
Use only earth colors. Your primary colors will be Indian Red, Yellow Ocher, and Prussian Blue.

You can even use the so-called Goya palette which use a cool transparent black in place of the blue. I HAVE ALSO SEEN THIS REFERED TO AS THE TETRACHROMATIC PALETTE.

The vivid colors available today date back to no earlier than the nineteenth century. Vivid colors prior to that were often very fugitive or very toxic and nearly always terribly expensive. They were used only with the greatest economy. Some were reac tive to oil and/or other pigments and had to be laid in with tempera before the oil colors were applied.

Also, emphasise the contrast in lighting for a chiascuro effect and paint on a dark ground such as a Burnt Sienna wash and use transparent glazes for the darks and opaque paint for the lights. The shiny highlights can be touched in over the finished painting with pure white mixed with a little egg yolk.


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What are mass tone and undertone in painting?

-- Mass tone, also called body color, is the value, hue and chroma of paint in a dense lump that reflects light off its surface rather than permitting it to pass through to the support (the canvas or other surface over which the paint is applied) and out again.

-- Undertone is the complex of those qualities that predominate when a paint is diluted or mechanically pulled out over a surface so that light penetrates down to the support and back out with a filtering action... undertone is also sometimes called "tint" since it can be evidenced when a color is dilute through mixing with another color.

-- Some colors are consistent in mass tone and undertone such as the phthalos, and some are unpredictable such as cobalt yellow that can have a muddy mass tone and brilliant undertone, or some earth colors that have warmer mass tones and cooler undertones. Gouache, opaque watercolor, is sometimes called "body color" because it has a pigment load or adulterant (chalk) that make it highly opaque and capable only of mass tone.


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What are the standard paint colors used by artists?

 :


The Pigment Palette in Netscape Safe Colors

These are the best Netscape HEXpalette matches I could come up with for the standard pigment colors. This chart will display properly only with 8bit color and Netscape 3.0 or higher.

The first column of high-key colors proceeds in spectral order. Colors to the right of these fully saturated colors are progressivly de-saturated forms of the given hue.

If the light colored text is difficult to read on your browser "select" the color names by click-sweeping over them with the mouse.


  [Ultramarine Blue]            
  [Phthalo Blue]   [Cerulean Blue]   [Prussian Blue]    
  [Blue-Green]   [Viridian]   [Prussian Green]    
  [Permanent Green]   [Chrome Oxide]   [Terre Verte]    
  [Sap Green]            
  [Yellow-Green]            
  [Lemon Yellow]   [Yellow Ochre]   [Raw Sienna]   [Raw Umber]
  [Orange]       [Burnt Sienna]    
  [Cadmium Red]   [Venetian Red]       [Burnt Umber]
  [Acra Red]            
  [Rose Madder]   [Indian Red]        
  [Dioxazine Purple]            
  [Cobalt Violet]   [Mars Violet]        
 
  [Titanium White]   [Buff Titanium]   [White + Blue]   [Lamp Black]
 


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©Daniel Wasserman



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