Color Management: A Comprehensive Guide for Graphic Designers

Introduction

Color, unlike any other subject in visual communications— interactive, print-based, environmental, and motion graphics—is very complex and frequently misunderstood. Color, which has physical, psychological, and/or learned behavioral attributes, can shape effective visual communication. As a physical form of communication—lightwaves—color is both absorbed and reflected by the objects we look at, and meaning is transformed and translated through its use. Color Management describes how to forecast the physical, psychological, and learned behavioral effects of color, and how to use color to create more meaningful messages. The Acuity Color System is available online at Allworth Press: www.allworth.com

As designers, we no longer need to know how to physically mix paint pigments in order to create a certain hue. Most of us have not touched a Prismacolor Pencil, Magic Marker, Color-aid paper, or paintbrush for nearly a decade. This book aims to provide designers with a resource for understanding the dynamics of color in the context of visual communication.

Color Management describes how to determine the distance at which letterforms can be seen in any color combination, for standard visions, including normal vision, minimum U.S. Division of Motor Vehicle standards, visually impaired, and legally blind standards. It is intended to help graphic designers, architects, environmental graphic designers, and sign manufacturers gain confidence in the preparation and production of signs and signage systems that use typographic forms and color combinations.

1 The Terminology of Color

Understanding the vernacular of color, considering the color complexity we deal with on a day-to-day basis, is often overwhelming. Unlike any other art discipline, visual communication deals not only with color building (the physical mixing of ink pigment and the creation of electronic files), but also with the human perception of hue, and the psychological effects and interpretations of color. This chapter is concerned with the language of color, its theories, and its use as a practical form of problemsolving. The terminology found in this chapter is the building block for understanding color dynamics, including subtractive color theory (both simple and complex color mixing), additive color theory, and 3-D color theory. Understanding the terms found within this chapter will broaden your color knowledge, thereby increasing the effectiveness of the visual messages you create.

Understanding color allows you to envision the power of visual messages, and a familiarity with color terminology will help you fully realize hue implications in the context of color theories, as well as in the context of print-based, interactive, environmental, and motion graphics. Strategies to understand effective color use are provided, including color legibility and readability using type and simple symbols, along with color matrices and paradigms. These strategies are demonstrated through exemplary professional work.

Figure 1

Art Directors Sarah A. Meyer, Ned Drew, and John T. Drew

Designer Sarah A. Meyer

Figure 1 The words Visual Thinking, the title of this volume, are concealed by a careful examination of the color value numbers associated with green. Within this example, subtle variations of green create a color effect— the words disappear when viewed at different angles. To ensure that an object or letterform can be viewed and understood at a distance, a 20% color value differential (CVD) is recommended. In the example above, the CVD is 5%.

Absorbed light: Light that is absorbed by an object; the opposite of transmitted light

All colors visible to humans are created by lightwaves. When light strikes an object, be it a rock or a printed surface, some lightwaves are absorbed by that object while others are reflected by its surface; this is what produces the object’s color. This is the essence of subtractive color theory. The lightwaves absorbed by an object are transformed into heat. The darker the color, the more waves are absorbed and thus the more heat it produces. An understanding of this phenomenon will help you make better decisions regarding outdoor color schemes (diagram 2).

Three-dimensional color theory specifies that if all light is absorbed by an object, the color produced is black. If only some of the lightwaves are absorbed by the object, with the others reflected by the surface into the human eye, these reflected lightwaves are transformed into electrical impulses which are interpreted by the primary visual cortex as color and object. The color value number indicates the relative lightness as perceived by the mind. This number represents how well the human eye perceives that color (diagram 3).

Diagram 1 The black and white combination creates a CVD of more than 40%, black being 2% and white being 98%. In reality neither color is absolute—0% or 100%. Numerous hues can be found in the 2–10% and 90–98% range, dispelling the myth that black and white color combinations are the most legible.

Diagram 2 To retrieve the heat index of a color, subtract the color value rating (in this book also referred to as Y tristimulus value) from 100%. This will yield the amount of absorbed light that is transformed into heat. The larger the number, the more heat produced. The PANTONE Color Cue can retrieve the Y tristimulus values for print production colors. If using a color not found within their systems, the Color Cue will give you the closest PANTONE Y tristimulus value. This is accurate enough to predict the color heat index.

1. 100% - 73.93% = 26.07%

2. 100% - 7.48% = 92.52%

3. 100% - 17.80% = 82.20%

4. 100% - 24.87% = 75.13%

5. 100% - 2.51% = 97.49%

6. 100% - 29.53% = 70.49%

We visited the stadium at Indian Wells Tennis Garden for the 2003 Super 9 event. The Indian Wells Tennis Garden is located in Palm Desert, California. The daytime temperatures when we attended were in the high 90s (mid-to-high 30s ˚C). The stadium seats are dark blue plastic, and we quickly found that you can fry an egg on them during the day. This is a good example of architects and environmental graphic designers having little understanding of the principles of subtractive color theory.

Color is always relative to the environment in which it is used. We should understand the environment in order to select effective colors. According to 3-D color theory, the light being reflected by an object and interpreted by the mind’s eye determines the color value. It is crucial for designers to know the color value numbers, including those for all ink- and plastic-matching systems. These numbers will help you understand the heat produced by different colors, and the contrast and legibility of color as perceived by the mind’s eye.

The lower the number, the more heat the object will produce. The heat of an object can be offset in many ways through manipulating the substrate. Taking the example of the Indian Wells stadium seats, two such ways of reducing the heat could have been: to place holes in them to increase ventilation and reduce their surface area; and to increase the substrate texture in order to create more scattering, thereby reducing the temperature.

In the 1980s and 1990s, a plethora of studies showed that a 40 percent contrast value between foreground and background is necessary in order for the legally blind/visually impaired to navigate their way through an environment.

Achromatic: Hues made from black, gray, and white

An achromatic color scheme can be an extremely effective communication device for the creation of visual messages. This type of color scheme is highly dramatic and, if used correctly, very emotive. Ansel Adams’ black-and-white photographs of the western United States, many of Georgia O’Keeffe’s paintings, and the movie Raging Bull are all fine examples of the employment of achromatic color schemes. Most contemporary designers are guilty of overlooking this particular color scheme in favor of using an array of colors. For example, few Web sites rely on an achromatic color scheme, and seldom do we see illustrations, posters, brochures, or annual reports in black and white. We tend to use black and white only when the budget does not allow for fourcolor reproduction, even when achromatic hues would be the most effective choice.

To create effective visual messages using achromatic color schemes, an understanding of how the many hues of black, white, and gray are created, and how the human eye perceives them, is necessary. It is harder to create an effective visual message using achromatic colors: an achromatic color scheme is inherently more simplistic than a multicolored scheme.

In complex color mixing, black is made from a combination of different hues. For example, in four-color process building, 100 percent of cyan, magenta, and yellow will create a dull black; black ink is added to create a rich and saturated printed surface with a greater tonal range. In addition, many two-spot-color combinations can create a range of blacks.

Diagram 3 To the right are the Y tristimulus values for the hues above. These demonstrate the relative lightness/darkness of an individual hue within the mind.

1. 73.93%

2. 7.48%

3. 17.80%

4. 24.87%

5. 2.51%

6. 29.53%

Diagram 4 The rods in the eyes have the ability to detect black, white, and gray.

Figure 2

Photographer Jenni Goldman

Figure 2 In this photograph, black, white, and continuous tones of gray are achieved to create the main focal point. The focal point is surrounded by white to effectively communicate the visual message of serenity. In printbased graphics these hues can be achieved in three different ways. The first is to create a one-color job using black. The second is to create a two-color job with neutral gray and black. Creating a duotone in Photoshop utilizing these two hues will create a printed specimen that rivals a continuous-tone photograph. By adding a second hue (gray), more tonality can be achieved within the printing process.

In print-based graphics, more often than not, white is created by the paper being used. If the paper has a high brightness rating, the white will be more brilliant, as will the other hues used. (The brightness rating for paper is always defined on the swatch provided by the manufacturer, or located on the ream itself.) If the paper is an off-white, then the inks printed on it will not have as wide a color spectrum—the colors will not be as vivid. Thus, in print-based graphics the paper used is the major building block for the color spectrum, which will be limited to the color value of the paper. If the paper is a light blue with a color value of 80 percent, the available range will be only 0–80 percent. In addition, all inks printed on this paper will have a tint (see color tinting) of blue. In some cases, white opaque ink is applied to colored paper before four-color process inks are printed on top. This links the color spectrum to the brightness rating of the white ink rather than the paper. Commercial screen-printing inks offer greater ink opacity for such use.

In environmental graphic design, white is usually created by applying a white paint, opaque white ink, or white pigment to a substrate. The same is true for any blacks or grays created for signage. It is important to know the color value of any hue, including black, white, and gray, in order to understand the contrast differential for legibility purposes, no matter the standard of eyesight. Most sign manufacturers have these numbers on file. The PANTONE® Color Cue™ gives the color curve for each hue specified within their system.

Diagram 5 (a–c)

The above color wheels are examples of different color models: 5a is a four-color process wheel; 5b is a 12-step traditional color wheel that is based in subtractive color theory; 5c is a color wheel derived from 3-D color theory specific to how the eye detects color.

In complex color mixing, gray is produced by combining multiple inks or colors. For example, in the Acuity Color System, many grays are created by equal screen percentages of cyan, magenta, and yellow. Gray can also be produced by mixing two secondary or tertiary colors located on opposite sides of the color wheel, in equal proportions.

In simple color mixing, gray is created by placing black and white side-by-side with no overlap. In print-based graphics, gray is created by using a screen percentage of black on white paper. This combines subtractive and simple additive color theory because some light is being absorbed, and color mixing is taking place in the brain.

According to additive color theory, black is produced by the absence of any light. To create black on a computer screen or television monitor, all light is prevented from reaching the area that is to appear black to the viewer.

According to 3-D color theory, black and white are detected by the photoreceptor cells found in the rods of the eyeball, located on the retina wall. Gray is created by a combination of photoreceptor cells responsible for detecting black and white. In the case of black, the photoreceptor cells within the rods create a negative electrical impulse that travels to the primary visual cortex, where it is interpreted by the mind.

Additive color theory/mixing: Combining lightwaves to create colors

Additive color is used in the production of print-based, environmental, interactive, and motion graphics. However, its use in print-based media is different from that in electronic media: in the print production phase, additive color is used to simulate subtractive color mixing. Due to the physical properties of additive color, the available spectrum of light is greater than that available for subtractive color. For example, on a computer screen, colors are created and projected directly into the human eye. No lightwaves are absorbed or reflected in any direction, by any objects. This is why the color on a computer screen will never match print-based graphics. In print-based graphics light, whether this be from the sun, a tungsten-filament lamp, or fluorescent lighting, is scattered by the object; some lightwaves are absorbed by it, leaving only a small portion to be directed into the human eye. Programming engineers have tried to simulate this phenomenon in order to create the appearance of subtractive colors on the computer screen. However, the color visible on the screen is not what appears on paper. This is due to the fact that each software application uses different programming for print-based production simulation. Since color is a product of its environment, the same spot color can look very different in different light sources, and no program can take the infinite amount of scenarios into account. Colors created according to additive color theory, for use in interactive and motiongraphic documents, are by-products of the intensity of the light they emit. A light source is measured in kelvins (K). Average daylight is measured at 5,000 K (U.S. standard) or 6,500 K (European standard). Every TV monitor, ATM, electronic kiosk, and computer screen may emit light from a different source. When designing interactive and motion graphics, it is important to make sure that the document is tested on many different models of monitors and computer systems, including those manufactured for DOS, Mac, and Unix, as the quality of the monitor and computer system will affect the color produced.

Diagram 6 (a–c)

The three gray bars are created using different color combinations: 6a creates variations of high warm gray through the use of redviolet and yellow-green; 6b creates variations of warm gray through the use of yellow and violet; 6c creates variations of a neutral gray using the process printing primaries cyan, magenta, and yellow.

Diagram 7 In the print dialog box of most ink-jet printers there are settings that incorporate average daylight (6,500 K) and early afternoon light (9,300 K). When printing, if a yellowish tint is laid down over the white areas of the paper, try one or both of these settings. By using either 6,500 K or 9,300 K the yellowish tint should be eliminated. These simulate the source of light in 3-D color theory, and most often help to render a better color printout.

Figure 3

Art Director/Designer Bas Jacobs

Figure 3 The design of this book is an excellent example of how afterimage can be utilized to create color dynamics not found on the printed page.

Afterimage: Illusions occurring when retinal cones and neurons become fatigued or overstimulated

Two categories of photoreceptor cells are responsible for human perception of color—red and green. (There is some debate within the medical community pertaining to another photoreceptor cell believed to be responsible for the perception of purple.) A photoreceptor cell can become fatigued if it fixates on a particular color. This will cause a false electrical impulse of the other color by the photoreceptor cell, creating what is called an afterimage. If we stare at an individual color for a minute or two and then look at a white background, we will see the color’s complementary. For instance, if we stare first at red, we will see green. This phenomenon is known as afterimage.

Afterimage can occur with graphics produced by both subtractive and additive color mixing. In both cases, the effect can be reduced by producing a composition that is kinetic. An asymmetric composition is far more active than a symmetric one. In an asymmetric composition, the eye tends not to rest and therefore, retinal fatigue is less likely to occur. If your aim is to create an afterimage effect, then a symmetric composition is recommended, as this will encourage the viewer’s eyes to rest.

Diagram 8 The use of afterimage can increase compositional movement, and at times, may alter meaning. Black, white, red, green, and blue correspond to the photoreceptor cells within the first stage of vision. When using colors that directly agree with the primaries found in 3-D color theory, afterimage will rapidly occur. The rods and cones will fire with force causing the receptor cells to become overly fatigued, hence inducing afterimage.

Designer John T. Drew and Sarah A. Meyer

Monochromatic, achromatic, and analogous color palettes are well suited to symmetric compositions. These palettes produce a constant electronic impulse that is either negative or positive, rather than both negative and positive, and therefore help to create a fixation point. This is not to say that they can’t be used for asymmetric compositions.

Analogous colors: A color grouping in which the colors are to the near left and right of each other

An analogous color scheme is harmonious in nature and can be highly effective in its subtleties. Analogous colors are harmonious because all colors within the palette have a certain percentage of each other built into them. This creates a visual lack of conflict and an exterior arrangement that is physically pleasing to the eye. As with monochromatic and achromatic color schemes, analogous color schemes are underutilized.

Within subtractive color theory, analogous color schemes involve complex subtractive mixing. Each color within the palette has a percentage of the other color, leading to complex color mixing because of the overlaying or overprinting of color in screen percentages on press.

Within 3-D color theory, analogous color schemes are physically pleasing to the eye because very little simultaneous contrast takes place. Cones within the eye are responsible for discerning color. Cones have two types of photoreceptor cells. One type discerns red, green, and blue, and the other blue/yellow, green/red, and black/white. (There is some debate over whether another type discerns purple.) Simultaneous contrast takes place when a photoreceptor cell is responsible for two colors that appear together. This creates an intermittent electrical impulse for both colors as they travel through the visual pathway to the primary visual cortex. For example, the color combination of green and red creates pronounced simultaneous contrast. The receptor cell responsible for green and red cannot physically process the information for both colors at the same time, thereby creating an unstable juxtaposition of color. With analogous colors, the photoreceptor cells responsible for the lightwaves within the color scheme fire continuously, creating very little simultaneous contrast. There is not an intermittent electrical impulse—the impulse is constant.

Bronzing: An effect that develops when some inks are exposed to light and air which creates a false reading in the calculation of color

Of particular importance in environmental graphic design, bronzing causes a glare effect in 3-D color space and must be accounted for in the creation of signs and signage systems. It occurs in inks that are warm in nature: the pigments in warm colors begin to rise up through the cooler ink pigments. This can reduce the legibility of signs as the color contrast, when the signs are viewed at a 45º angle, will be affected over time. This creates an unusual amount of glare, almost equivalent to laminating or placing a sign under glass. For this reason, bronzing must be accounted for when choosing spot colors or four-color process builds that have a mixture of warm and cool colors, for example, cyan and magenta, reflex blue and rubine red. Bronzing is most apparent in the family of purples. When measuring color, a fresh color sample will ensure a correct measurement.

Diagram 9 A facsimile of how bronzing may occur and alter the purple hue.

Diagram 10 An illustration of Lambert’s law.

Diagram 11 (a and b)

In 11a, all other light not reflected off the surface is absorbed as heat. This is an example of simple subtractive color mixing. In 11b, heat absorption is less. This is an example of complex subtractive color mixing.

In print-based graphics, bronzing should be accounted for when creating documents that are meant to be viewed from a distance, as billboards, broadsides, posters, and food packaging are all intended to be. This is not to say that colors prone to bronzing should not be used in the creation of any sign, signage system, poster, billboard, and the like. It simply means that legibility should be increased by 10 percent to allow for this effect: the reduction in legibility due to lightwaves being scattered when a document is under glass is equivalent to 10 percent.

The same 10-percent rule applies to electronic media in which glare is an issue. When lightwaves reflect off of a mirrorlike or smooth surface, scattering or glare will occur. This 10 percent increase takes into account only a minimum amount of glare. There is no known equation in the calculation of color to account for severe glare. However, creating a document that is on a slightly textured substrate, equivalent to a matte finish, can sometimes cut down on glare.

Bronzing occurs only with the subtractive color