网络出版中文字背景色的优化

网络出版的阅读基于屏幕显示,不同于纸质出版,显示屏幕上呈现文字信息可不拘泥于白色背景。实验针对不同字体和字号的黑色文字,设计了亮白和红、黄、绿、蓝、品红、灰等不同色相的背景颜色,并在一定范围内改变其明亮度和彩度。视觉观测结果表明,因屏幕自发光的亮度很大,其最亮的白色并不适于黑色文字的显示,适合的白色背景是明亮度降低后的一定范围内的灰色。类似地,其他所实验的彩色,适于作为背景色的明度和彩度也都有一定的范围。就适于的范围大小比较而言,包括灰色在内,灰色、黄色、绿色和蓝色的明度范围明显大于红色和品红色;绿色、黄色和蓝色的彩度范围也明显大于红色和品红色,其中绿色的彩度范围尤为宽泛。     

Hue,chroma, and lightness preference in Chinese adults: Age and gender differences

Recent studies have shown cultural differences in color preference. However, the color preference of people in China, which was found to have its own pattern, was yet to be studied in depth. The current study investigated color preference and the associated age and gender differences in an adult national sample (N = 1290) to provide a culture‐specific characteristic of color perception. Participants rated how much they liked each of 31 colors (four chroma‐lightness levels of red, orange, yellow, green, cyan, blue, and purple, plus three achromatic colors). We found a unique saturated color preference pattern characterized by red, cyan, and blue being preferred the most and orange as the least preferred chromatic color. The “red preference” phenomenon was observed in Chinese adults. Light colors were preferred the most in terms of chroma‐lightness level, followed by saturated, muted, and dark colors. The results of a principal component analysis of the 28 chromatic colors showed that blue‐green‐like colors (cool colors) constituted the largest proportion of color preference. The preference for orange and several dark colors increased with age, while that for bluish colors, purple, yellow, white, black, and light colors decreased. In terms of gender, women liked cyan, white, pink, and light colors and disliked red, orange, and dark colors more than men did. Our findings provide new empirical evidence about the color preference of Chinese and may offer some insight into the study of color preference and lay the foundations for future theoretical and practical research.     

Color identification data obtained from photopic to mesopic illuminance levels

To use colors properly as an aid in visual tasks, it is necessary to know how colors are identified under various illuminating environments. In this study color identification was examined under a wide range of illuminances, from photopic to mesopic levels. Fifteen subjects named a color chip using one of the preselected color terms: red, orange, yellow, yellow‐green, green, blue‐green, blue, purple, pink, brown, white, gray, and black. The 256 color chips were selected from value planes of 4, 6, and 8 of the Munsell color space. The illuminance levels tested were 1000, 10, 1, and 0.1 lx. At 1000 lx the color chips were identified consistently by each of the color terms. At 10 lx the pattern of color identification was very similar to that at 1000 lx, though the consistency of the identification evidently declined. At 1 lx great changes in color identification occurred. By 0.1 lx reliable color identification was completely lost, though blue and red responses remained. At the lower illuminances green was replaced with blue, and red, orange, and pink were frequently confused with each other. However, the border between blue and purple was almost constant. These results provide a scientific basis for the appropriate use of colors in various illuminating environments. Also, they are useful for studies in color appearance modeling. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 252–259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10065     

The fifteen causes of color: The physics and chemistry of color

The fifteen causes of color derived from a variety of physical and chemical mechanisms are summarized in five Croups in this article. Vibrations and simple excitations explain the colors of incandescence (e.g., flames), gas excitations (neon tube, aurora), and vibrations and rotations (blue ice and water). Ligand-field-effect colors are seen in transition-metal compounds (turquoise, chrome-oxide green) and impurities (ruby, emerald). Molecular orbitals explain the colors of organic compounds (indigo, chlorophyll) and charge-transfer compounds (blue sapphire, lapis lazuli). Energy bands are involved in the colors of metals and alloys (gold, brass), of semiconductors (cadmium yellow, vermillion), doped semiconductors (blue and yellow diamond), and color centers (amethyst, topaz). Geometrical and physical optics are involved in the colors derived from dispersive refraction (rainbow, green flash), scattering(blue sky, blue eyes, red sunset), interference (soap bubbles, iridescent beetles), and diffraction (the corona aureole, opal).     

Categorical color constancy under RGB‐LED light sources

The light‐emitting diode (LED)‐based light sources have been widely applied across numerous industries and in everyday practical uses. Recently, the LED‐based light source consisting of red, green and blue LEDs with narrow spectral bands (RGB‐LED) has been a more preferred illumination source than the common white phosphor LED and other traditional broadband light sources because the RGB‐LED can create many types of illumination color. The color rendering index of the RGB‐LED, however, is considerably lower compared to the traditional broadband light sources and the multi‐band LED light source (MB‐LED), which is composed of several LEDs and can accurately simulate daylight illuminants. Considering 3 relatively narrow spectral bands of the RGB‐LED light source, the color constancy, which is referred to as the ability of the human visual system to attenuate influences of illumination color change and hold the perception of a surface color constant, may be worse under the RGB‐LED light source than under the traditional broadband light sources or under the MB‐LED. In this study, we investigated categorical color constancy using a color naming method with real Munsell color chips under illumination changes from neutral to red, green, blue, and yellow illuminations. The neutral and 4 chromatic illuminants were produced by the RGB‐LED light source. A modified use of the color constancy index, which describes a centroid shift of each color category, was introduced to evaluate the color constancy performance. The results revealed that categorical color constancy under the 4 chromatic illuminants held relatively well, except for the red, brown, orange, and yellow color categories under the blue illumination and the orange color category under the yellow illumination. Furthermore, the categorical color constancy under red and green illuminations was better than the categorical color constancy under blue and yellow illuminations. The results indicate that a color constancy mechanism in the visual system functions in color categories when the illuminant emits an insufficient spectrum to render the colors of reflecting surfaces accurately. However, it is not recommended to use the RGB‐LED light source to produce blue and yellow illuminations because of the poor color constancy.     

Quantitative representation of floral colors

Human and insect pollinator perceived floral colors of 81 species of angiosperms (flowering plants) from Trivandrum (Kerala, India) was represented using the CIE 1976 L*a*b* color space and color hexagon, respectively. The floral color difference among human perceived red, yellow, and blue‐hued flowers and that of each flower from its respective pure hue was calculated using the CIE ΔE 2000 formula. Human perceived floral color difference values were consistently higher than 3.5, indicating the uniqueness of floral colors. Flowers perceived red and yellow by humans were dominant and of comparable proportions. Insect pollinators perceive most of the flowers as blue‐green. Quantitative representation of human and pollinator perceived floral colors would be invaluable to understand the information broadcasted by flowers. It can form the basis of flower grading in the floriculture industry and underpin objectivity in evolving the framework for national pollinator strategies.     

Did the CIE get it right? A critical test of the CIE color domains for signal lights

Since 1951, the Commission Internationale de L'Eclairage (CIE) has provided influential guidance on the choice of the most suitable colors for colored signal lights. In 1994, the CIE reviewed its 1975 recommendations for signal colors and has recently revised them. These revised recommendations have now been published as a CIE standard. This article reports an experiment designed to test those recommendations and to provide data on the reliability of signal color recognition under a range of conditions. Thirty young subjects (aged 18–28 years) and thirty older subjects (aged 50–64 years) named the colors of lights, the colors of which were located on or close to the color boundaries defined by the CIE for red, yellow, white, green, and blue colors. The angular diameter of the light was one min of arc. In a second experiment, half the subjects named the colors of the lights when the angular diameter was 5 min of arc. Observations were made under both dark and light adaptation. Red signals, especially those located in the CIE Class A domain, were reliably recognized under all conditions. Yellow near the red boundary of the CIE yellow domain tended to be confused with red, especially under dark adapted conditions at low signal illuminances. White was not a reliable signal color and was often confused with yellow, except for a white located near the blue boundary of CIE white. Green colors located near the blue boundary of the CIE color domain for green were less reliably recognized than those of longer dominant wavelength. Blue signal colors located within the CIE Class A blue domain were more reliable than expected, except at very low signal illuminances. There were significant differences in the performance of older compared to younger subjects, some of which can be explained by color shifts occurring as the result of the yellowing of the lens of the eye with age. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 109–122, 2001     

EFFECT OF VARIATIONS IN COLOR STAINS AND FRITS ON COLORS PRODUCED IN PORCELAIN ENAMELS*

A representative series of colors, blue, brown, green, red, and yellow, was selected for this investigation. Variations of the constituents for these five stains were made and the resulting colors produced in the enamels were measured by means of spectrophotometric curves. The influence of additions of barium oxide, lead oxide, and zinc oxide to the frit was also studied. The addition of lead oxide to the frit tended to give greater solution of the blue stains. The barium oxide additions dissolved the lead antimonate yellow the most, while the lead oxide had the least effect on the yellow stains. Variations in calcination temperatures of the red stains produced decided changes in color. The additions of lead oxide darkened the color produced with the red stains.     

Hue cycle described by graphs and color names

The color appearance of the hue cycle in equal radiance is described in hue, saturation, and brightness/lightness. The latter does not resemble CIE luminance Y (peaking at 555 nm green), but peaks near 570 nm yellow with minor peaks near 490 nm cyan and 530 c magenta. Saturation per watt peaks near 450, 530, 610 nm (blue, green, red). Newton's choice of seven spectrum colors, and particularly his two bluish colors, is explained as major colors rather than merely different hues.     

Three are Not Enough: An INDSCAL Analysis Suggesting that Color Space Has Seven (£1) Dimensions

Forty-five subjects, including color normals, protanomalous, deuteranomalous, protanopes, and deuteranopes, judged dissimilarities of 26 Munsell color chips chosen to span the full color space (i.e., all three parameters—hue, saturation, and lightness—were varied). Each of the 325 pairs of colors was mounted on a standard grey background board. They were presented to subjects in different random orders and were viewed under a Macbeth daylight lamp. For each pair the subject circled a number varying from 0 (for “identical”) to 9 (for “maximally dissimilar”). Fifty data matrices obtained from 45 subjects (5 were from the same subject on different dates and 2 were from another subject) were analyzed by the INDSCAL method. The three-dimensional solution yielded the “standard” three dimensions (lightness, red-green, and yellow-blue) with the classical “color circle” emerging, in a slightly distorted form, in the plane of the second and third dimensions. Seven dimensions seemed necessary to account fully for these data, however. In seven dimensions each of the “standard” dimensions is paired with a “folded” version. Accompanying lightness is a “folded” lightness dimensions, which we have called “lightness contrast.” The light and dark colors are at one end, contrasted with medium colors at the other. Similarly, “folded” red-green roughly contrasts red and green with blue, yellow, and the greys, while “folded” yellow-blue contrasts blue and yellow with red, green, and the greys. The seventh dimension, which may be artifactual, was called “split yellow.” It contrasts very brilliant (high Munsell value and chroma) yellow and orange colors with all the other colors. It is speculated that some of these extra dimensions may relate to anomalous receptor processes characteristic of deviant subjects. The INDSCAL subject space enables discrimination among all five subject types. Specifically, one of the “natural planes” (the red-green versus “folded” yellow-blue plane) of the seven-dimensional solution can be divided into contiguous and fairly compact regions, with each subject type occupying a unique region.     

Gray and grayness—its complexities in color appearance of surface colors

Complexities on the roles of reference color gray and grayness are reviewed. They are essential in color appearance, but gray is an implicit color. Although “grayness” is not explicitly used in visual color assessment of surface colors or color order systems, gray can be combined with any colors having six primary‐color components using the term “grayish,” for example, grayish red and grayish yellow. However, the existing region of grayness is limited in a part of color‐appearance space. Illuminance dependency of gray perception is also clarified. Existence of two kinds of psychometric quantities are suggested: one is the attribute of grayness based on its psychological amount in a grayish color under study, and the other is the attribute of brightness of the grayish color under a specified illuminance, psychophysical quantity. The Nayatani‐Theoretical color order system, which uses three opponent‐colors axes, can clarify the above complexities of gray and grayness. Its importance is the same as six primary colors, red–green, yellow–blue, and white–black. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 37–44, 2014     

Effects of nine monochromatic office interior colors on clerical tasks and worker mood

A pre- and post-between groups experimental design with nine treatment groups was conducted to determine the effects of interior office colors on subjects' clerical task performance, mood, and color preference. A total of 675 subjects participated in the study. The dependent variables were proofreading performance tasks, six mood states, and color preference. Independent variables were nine office colors, two saturation levels (high or low), two value levels (dark or light), warmth or coolness of the colors, and gender. The data were analyzed by using multivariate analyses of covariance and analyses of variance. The results showed that subjects made significantly more proofreading errors in the white office than in the blue and red offices. Females performed significantly better than males. Moreover, the saturation of the colors seemed to be a salient predictor of differences between females and males. Females indicated more depression, confusion, and anger in low-saturated office colors (white, gray, beige), whereas males reported more depression, confusion, and anger in the high-saturated office colors (green, blue, purple, red, yellow, and orange). Further, subjects revealed that they would be least likely to work in the orange and purple color offices and prefer to work in the beige and white offices. Implications for future research on the effects of colors on office worker performance and mood are discussed. © 1996 John Wiley & Sons, Inc.     

Color and women hitchhikers' attractiveness: Gentlemen drivers prefer red

Research has shown that with some nonhuman primates, red is associated with greater sexual attractiveness of females. Five female confederates in their early 20s posed as hitchhikers wearing T‐shirts of different colors (black, white, red, blue, green, or yellow). It was found that the women wearing red solicited a higher response in the number of male drivers who stopped to offer a ride. No color effect was found when considering the behavior of female drivers. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2012     

Hue and warm‐cool feeling as the visual resemblance criteria for iso‐CCT judgment

The hue perception and ‘warm‐cool’ feelings were investigated, in response to various lighting settings, following the adaptation to either 3500K or 5000K to compare which one—between conventional iso‐Correlated Color Temperature (CCT) and a new one based on CIE u'v′ color space—is more compatible with the visual perception. Twenty participants evaluated hue and warm‐cool feelings for 48 test lighting settings, by observing an empty gray booth. The results showed that yellow‐blue and ‘warm‐cool’ feelings are closely located around the Planckian locus, while red‐green roughly follows the line orthogonal to the Planckian locus in CIE u'v′ color space, at both 3500 K and 5000 K settings. This suggests that u'v′ color space correlates better with human perception.     

Similarities and differences between male and female novice designers on color‐concept associations for warnings,action required,and signs and equipment status messages

This research examined the male and female novice designers toward color associations for the concepts used for ‘warnings’, ‘action required’, and ‘signs and equipment status’ through a questionnaire‐based study. A total of 178 Hong Kong Chinese final year undergraduate design students (89 males and 89 females) participated in the study. The test used required the participants to indicate their choice of one of nine colors to associations with each of 38 concepts in a color‐concept table, so that any one color could be associated with any one of the concepts. For both male and female groups of novice designers, chi‐square tests revealed a strong color association for each concept tested in this study (P < .05). The results showed males and females agreed on some color‐concept association stereotypes which were therefore gender neutral. The male and female novice designers had the same color associations and similar levels of stereotype strengths for 21 concepts. The nine strongest and therefore most useful color‐concept association stereotypes for both male and female novice designers were: red‐danger, red‐fire, red‐hot, red‐stop, red‐emergency, red‐error, blue‐cold, blue‐male, and green‐exit. However, the male and female novice designers had different color association stereotypes for the standby (green vs. yellow), emergency exit (green vs. red), and toxic (purple vs. black) concepts, and the strengths of the 14 remaining associations for both groups were not at equivalent levels. Overall, it is anticipated that the findings of this study will act as a useful reference for novice designers and other design practitioners to optimize color coding in the design of ‘warnings’, ‘action required’, and ‘signs and equipment status’ messages.     

The appearance of colors produced by a minimum-energy stimulus and two pairs of fundamental colors

This article presents the results of experiments designed to measure the color appearance produced by a minimum-energy stimulus within very small color fields and exposed for a very short duration. The experiments also revealed the common nature of colors in both spatial and temporal reductions. The hue is shifted toward either red or green and then toward a line connecting yellow and blue on the chromaticity diagram. The decrease and increase in saturation and brightness, respectively, correspond to this variation in hue. The nature of the results pertaining to the mechanism of color perception led to the assumption that a color-sensation mechanism consisting of two pairs of fundamental colors acted functionally. These fundamental colors were calculated from the variations of the results obtained in color space, and were defined respectively as 513C, 510, 585, and 484 nm.     

Computerized Color Distinguishing System for Color Printed Fabric by Using the Approach of Probabilistic Neural Network

This article proposes an innovative color printed fabric computer color distinguishing system whose main functions are to precisely distinguish the printed fabric pattern colors and match colors to improve the current time-consuming color distinguishing conducted by manpower. The RGB color mode is an industrial color standard, by which the change and overlapping of color channels of red, green, and blue represent types of colors. RGB stands for red, green, and blue, respectively. It is one of the most widely used color system and covers almost all of the colors sensible to human vision. Hence, this paper adopts the RGB color mode to present color printed fabric images. First, to reduce the color distinguishing computation, a genetic algorithm was applied in search of small images of the same color in the original color printed fabric. Then, color distinguishing computation was conducted by a probabilistic neural network (PNN), which has the advantage of a very fast learning speed. Finally, PANTONE® standard color tickets were applied in matching colors. The experimental results revealed that the PNN design can easily realize and achieve accurate, fast color classification. It is proved that this color distinguishing system can be practically applied in printed fabric color distinguishing and matching.     

Classification of colors through fuzzy statistical experiment

The membership function describing the degree of association of a color sample to a specified color name is estimated experimentally through fuzzy statistical experiment. Here, we are interested in the surface color of opaque materials including red, orange, yellow, green, blue, purple, white, gray, and black. The characteristics of the membership function for these colors are found to be affected appreciably by the light source used.     

Color rendering: Asking the question

Two white lights may have the same chromaticity, and yet when used to light an array of objects may differ in their ability to reveal colors. For example, any white light can be matched by a mixture of two narrow‐band lights, a yellow plus a blue. In this extreme case, reds and greens become black or brown and the red‐green dimension is lost. At the other extreme, a light with three narrow bands, at the proper wavelengths, can brighten reds and greens and increase red‐green contrast, relative to a broad‐band light such as daylight. Many commercial lights tend to dull reds and greens, relative to broad‐band sources, a central reason that color rendering is a practical concern. A telling example is neodymium glass, a yellow‐absorbing filter that is sometimes used to improve color rendering. This article seeks to bring these ideas to life through detailed graphical examples. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 403–412, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10193     

Color Stability of Clear and Opaque Titania Enamels Containing Various Color Oxides

A study was made of the spectrophotometric characteristics of a clear and an opaque titania-bearing enamel. Three and six per cent additions of green, blue, brown, and red oxides were made to the base enamels. After firing the enameled samples over a range of time and temperature, spectrcphotometric and X-ray data were obtained. The results indicate that the lack of stability of the opaque colored enamels is due to the change from a blue-white to a cream-white color on increased firing treatment. The addition of a cream component tends to shift the hue of the fired enamel toward the red end of the visible spectrum. The green and the blue colors were much less stable than the red. X-ray data show that the total anatase present decreases, which is evidence that a cream-white color developed. X-ray data did not indicate any change in crystal structure of the anatase, rutile, or color oxide. Titania present in the glass of the clear enamel did not cause color instability.