Color analysis of natural colorant‐dyed fabrics

Colors from naturally dyed fabrics recently have attracted both consumers and manufacturers in fashion markets. Even though color attributes of the fabrics have been partially observed in some literature, a data base of colors for natural colorants in fabrics needs to be established and the colors to be characterized according to systematic color notations and tones in order to relate the traditional natural colors to contemporary color communication systems. Therefore, a study was performed to investigate color characteristics for a given large set of natural colorants‐dyed fabrics based on the Munsell color notations, to analyze their tones with relation to the notation such as hue, value, and chroma, and finally to identify the effects of mordanting, an important coloring auxiliary, on the colorimetric properties of the fabrics. As a result, the dominant hue for a total of 350 naturally dyed fabrics was yellowish families followed by reddish and purplish ones in the Munsell notation owing to the use of leaves and plant as usual natural dyestuff, which confirms the limit of color hues of the fabrics. Color value for most of naturally dyed fabrics was generally higher whereas the chroma was lower, which means that most of colors for naturally dyed fabrics tended to be bright and weak shaded. Grayish, light grayish, and soft tones were the main tones of natural colorant‐dyed fabrics. All of hue, value, and chroma were found as being influenced by mordanting in that more particularly; iron mordanting was likely to cause the decrease of both value and chroma for most of naturally dyed fabrics. These results could provide a systematic color data for naturally dyed fashion fabrics and suggest a future direction of color development for them. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 148–157, 2008     

A comparative analysis of the characteristics and images of costume colors in the traditional plays of Korea,China, and Japan

The purpose of this study was to analyze quantitatively the characteristics and images of costume colors in the traditional plays of Korea, China, and Japan. The study focused on the Korean Masque, Beijing Opera, and Kabuki costume colors based on a selection of 1135 color samples. The collected source data were selected by extracting digital color data by using the Eyedropper Tool of Photoshop 7.0. The RGB color data were transformed to H V/C and the attributes of hue and tone were analyzed. Color images were analyzed with the color image scales of IRI Color Design Institute and Shigenobu Kobayashi to increase the validity of the evaluated images. As a result, the “five element colors (red, yellow, purple–blue (PB), white, and black)” from the theory of “Yin‐Yang Wu‐Xing” were used in the common stage costume colors of the Korean Masque, Beijing Opera, and Kabuki. Red, a preferred Asian color, was used most frequently in the costumes of these three traditional plays. A comparison of the traditional stage costume colors in the three northeast Asian countries revealed a difference in tones rather than in hues. First, the Korean Masque frequently used white in accordance with the tradition of white‐clad people and the cultural view of colors in which natural colors were preferred. Additionally, in the Masque, Koreans used colors based on the theory of Yin‐Yang Wu‐Xing with high‐chroma tones. On the other hand, the Beijing Opera exhibited the gorgeous and strong color images of China, by adopting high‐chroma colors in the Five Element Color: R, Y, PB, white, and black. Last, in the Kabuki costumes, a variety of white, black, dull, light, dark, strong, vivid, deep, bright, and grayish tones played an important role in showing various color images. The costume color images of the traditional plays of the three countries revealed that all shared the use of dynamic, springy/casual, and gorgeous images in the strong contrast of five element colors. Regarding the differences, the Korean Masque exhibited natural images in favor of natural colors, whereas the Kabuki displayed modern, decent/formal images by using dull, dark, and grayish colors. The study results suggested that the three countries commonly used five element colors from the theory of Yin‐Yang Wu‐Xing, but that their color images differed in terms of the tones used and the techniques for color combination. These results reflect that colors in the traditional costumes of the three countries are affected by their cultural codes, thereby representing the characteristics ofcertain peoples and cultural circles. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011     

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     

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.     

A study of color differences in women's ready‐to‐wear collections from world fashion cities: Intensive study of the Fall/Winter 2010 collections from New York,London, Milan,and Paris

The purpose of this study is to analyze the color differences in the four fashion collections from New York, London, Milan, and Paris while focusing on 2010 Fall and Winter women's ready‐to‐wear collections. The colors of the fashion collections were collected from American Vogue's website www.style.com and analyzed by using the ISCC –NBS color system which is made up of 10 basic hues of pink, red, orange, brown, yellow, olive, yellow green, green, blue, and purple, and three neutral categories of white, gray, and black. In addition to these 13 categories, yellowish pink, gold, and silver categories were classified. For analysis, one‐way ANOVA, the Scheffe test and the t‐test were adopted. The result of analysis showed that there was a statistical difference in purple compared with the other colors examined. The London collection showed the highest ratio of use in purple, whereas the Milan collection contrarily showed the lowest ratio of use in purple. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 463–468, 2013     

Unique hue judgments using saturated and desaturated Munsell samples under different light sources

Past studies investigating the unique hues only used samples with a relatively high saturation levels under standard illuminants. In this study, 10 observers selected the four samples with unique hues from 40 V6C8 (Value 6 Chroma 8) and 40 V8C4 (Value 8 Chroma 4) Munsell samples under six light sources, comprising three levels of D_uv (i.e., 0, ?0.02, and ?0.04) and two levels of correlated color temperature (i.e., 2700 and 3500 K). Significant differences were found between the two chroma levels for unique blue and yellow, with the hue angles of unique yellow and blue judged using the desaturated samples being significantly different from those defined in CIECAM02. The iso‐lines of unique yellow, blue, and green did not always go through the origin of the a*‐b* or a′‐b′ planes in CIELAB and CAM02‐UCS. Thus, the problems of CIECAM02, CIELAB, and CAM02‐UCS identified in this study need further investigations.     

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.     

Variability in Unique Hue Selection: A Surprising Phenomenon

Data from ten different experiments involving nearly 600 observers of determination of unique hues are compared. Six experiments involve determination using spectral lights; two use desaturated monitor colors, and the remaining two use color chip sets. Except for unique green, color chips result in narrower ranges of results than spectral lights. Unique green has a surprisingly large range of variation in both spectral light and color chip experiments, followed by red. Comparison of spectral light data indicates that one observer's unique blue can be another's unique green and vice versa, and the same for yellow and green. This finding raises significant questions for color appearance and color space/difference models, as well as philosophy of color. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 158–162, 2004;Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10237     

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.     

Effect of area on color harmony in simulated interiors

The main aim of this study is to examine the effect of area on color harmony in simulated interior spaces. The secondary aim of the study is to investigate how the term color harmony is defined and the link between color harmony and related terms used to define it. These terms can explain why a color scheme is evaluated as harmonious. Four sets of three-color combinations created by using the hues red, blue, yellow, green, purple, and orange were studied in a simulated office interior emphasizing different proportional use of each color. Firstly, participants evaluated harmony content of the images. Secondly, they evaluated each image regarding the terms related to color harmony. Findings indicated that area had an effect on color harmony for two of the color combinations (warm & cool). However, there were no strong but rather moderate and weak correlations between color harmony and the terms.     

Individual differences of unique hue loci and their relation to color preferences

Loci of the four unique hues (red, green, blue, and yellow) on the equiluminant plane on the color display and three preferred colors were obtained from 115 normal trichromats. We sought possible correlations between these measures. Different unique hue loci were not correlated with each other. The three preferred colors were not correlated with each other. We found five combinations of significant correlation between a preferred color and unique hue settings, yet the overall tendency is not very clear. We conclude that individual differences in color appearance measured by unique hues and color preferences measured by asking for favorite colors may not be predicted from each other or even within a category because the differences in the earlier visual mechanisms can be compensated for and these high‐level measures can be influenced by learning and experience. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 285–291, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20023     

荧光增白剂对纯棉织物洗涤效果的影响

采用添加不同种类和用量荧光增白剂的标准洗衣液洗涤不同颜色纯棉织物,对比分析洗涤后织物的L*,a*,b*和C*值,反射率曲线以及目视评价结果,得到荧光增白剂对不同颜色纯棉织物的影响效果。结果表明,荧光增白剂可使增白布更白,漂白和米白布明显变亮白,浅蓝和粉红布样更加艳丽,浅灰和浅黄布样泛白或变浅,使卡其布样明显泛白,对大红、深蓝、黑色等深色纯棉织物无明显影响。     

What color do you feel? Color choices are driven by mood

Popular opinion holds that color has specific affective meaning. Brighter, more chromatic, and warm colors were conceptually linked to positive stimuli and darker, less chromatic, and cool colors to negative stimuli. Whether such systematic color associations exist with actually mood felt remains to be tested. We experimentally induced four moods—joy, relaxation, fear, and sadness—in a between‐subject design (N = 96). Subsequently, we asked participants to select a color, from an unrestricted sample, best representing their current mood. Color choices differed between moods on hue, lightness, and chroma. Yellow hues were systematically associated with joy while yellow‐green hues with relaxation. Lighter colors were matched to joy and relaxation (positive moods) than fear and sadness (negative moods). Most chromatic colors were matched to joy, then relaxation, fear, and sadness. We conclude that color choices represent felt mood to some extent, after accounting for a relatively low specificity for color‐mood associations.     

The role of copper and silver in the colouration of metallic luster decorations (Tunisia, 9th century; Mesopotamia, 10th century; Sicily, 16th century): A first approach

The metallic luster of glazed ceramics is a very special type of decoration. Its optical properties are characterized by a change of colour according to the observation conditions. In diffuse light, these decorations are often green, brown, or ochre‐yellow. In specular reflection, they show an associated coloured metallic reflection (blue, golden‐yellow, orange, etc.). Metallic copper and/or silver colloids almost always compose the metallic luster decorations. We wish to define the role of these two metals in the colouration observed both in diffuse light and in specular reflection. Our investigations show that a relationship exists between the proportions of copper and silver, and the diffuse colour. The green decorations contain more silver than copper, and the ochre‐yellow and brown decorations contain more copper than silver. This specific correlation only exists if the samples have the same type of glaze and, especially, a similar chemical composition. This means that the composition of the glaze has an important influence in the colouration process. Moreover, our investigations show that there is no relationship between the specular colour and the overall concentration of copper and silver. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 352–359, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10183     

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.     

Preparation and characterization of green reflective films of polyaniline analogs containing azobenzene units

Pd‐catalyzed polycondensation of aniline derivatives and 4,4′‐dibromoazobenzene affords polyaniline analogs containing azobenzene units. The polymers are red in solution and in thin films state, whereas they have a green luster in thick films. Substitution of 4,4′‐dibromoazobenzene for 4,4′‐dibromostilbene changes the reflection color from green to blue, whereas the introduction of a non‐conjugated unit slightly affects the reflection color. The glossiness of the film is dependent on the smoothness of the film surface. The reflectance measurements using polarized light reveal that reflection spectra correlate well with the complex refractive index (ñ = n + ik) of the film. These results confirm that the green luster can be attributed to the uniform surface reflection of the object, which has a large refractive index and absorption coefficient at around 500 nm. The polymer films exhibit good transmission of radio frequency signals owing to the lack of free electron carriers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41275.     

Experimental object color unique hue data for the mean observer for color appearance modeling

Color appearance models, among other things, predict the hue of a stimulus when compared with defined stimuli that represent the four unique hues. Recent studies have indicated that the stimuli representing with high reliability unique hue (UH) percepts vary widely for different color‐normal observers. The average yellow and blue UH stimuli for 102 observers, as determined in a recent experiment at medium chroma, differ considerably from the CIECAM02 defined unique hues, based on the Swedish NCS. Wide inter‐observer variability precludes color appearance models from accurately predicting, for individual observers, all four unique hue stimuli. However, models should predict accurately those of a well‐defined average observer. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 505–506, 2008     

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.     

Effect of texture on color variation in inkjet‐printed woven textiles

Inkjet‐printed textiles are influenced by a wide range of parameters due to highly diverse textile structures and the resulting textures. The goal of this study is to understand the effect of texture on color appearance in inkjet‐printed woven textiles. Cotton‐woven samples were constructed with nine different weave structures. Each sample was digitally printed with identical squares of primary colors cyan, magenta, and yellow and secondary colors red, green, and blue. The amount of ink applied was controlled consistently with an image editing software. CIE L* values were calculated from the measured reflectance. 25 observers ranked the perceived texture and color lightness of each sample. Perceived visual texture and perceived color lightness scales were estimated from the rankings using the rank order method. The measured CIE L* values and the scale of perceived lightness were positively related for the primary and secondary colors. Instrumental measurements of the textile surface characteristics were positively related to the visual scale. Texture was demonstrated to cause a measurable effect on color results in inkjet printing, both using instrumental and perceptual measures. To investigate if the color differences were substantial enough to cause “out of tolerance” ratings in textiles based on common textile industry color acceptance procedures, color differences among the samples were calculated and compared to a reference sample. Results demonstrated that color variation due to texture was sufficient to lead to rejection of a printed color in comparison to a color specification. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 297–303, 2015     

Practical color barrier‐free illumination for deuteranopia using LEDs

Here, we propose a color barrier‐free illumination consisting of white, red, and blue LEDs for people with deuteranopia‐type defects in color perception. Color perceptions of 20 volunteers with normal vision and four examinees of deuteranopia were evaluated by both the Ishihara test for color blindness and the Farnsworth Panel D‐15 test under color barrier‐free illumination. The illumination was comparably effective, not only for discriminating between red and green but also for discrimination of the hues on a color chip continuously. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 218–223, 2015