Experimental determination of laws of color harmony. Part 3: Harmony content of different hue pairs

At the Budapest University of Technology and Economics in 1956, we decided to start large‐scale experiments on color harmony. The experiments and the processing of the experimental data were completed in 2006. The experiments described in this article were based on a long established experience that harmony content of different hue pairs greatly differ from each other. The vast majority of former research activities on the subject of color harmony narrowed down mostly to investigations of saturated color pairs. Color samples of our experiments have been defined within the color space of the Coloroid color system, built on harmony thresholds. The compositions, prepared for the experiments, always consisted of two saturated hues and three low saturation colors of each hue at varying brightness, making it a total of eight colors. Within the framework of the experiments, 48 hues were used. Out of these, each of the 24 was formed into composition pairs with the remaining 48 hues, forming a total of 852 compositions. The paired‐comparison experiments were conducted with the use of the compositions prepared by collage technique. Color samples made of painted paper, between 1980 and 1985, have been repeated between 2002 and 2006 with the same color selection but with computer‐generated pseudorandom patch system compositions. It has been established that harmony content of hue pairs can be expressed by the relative angle of their hue planes in the Coloroid color space. The harmony content of hue pairs exceeds that of other pairs, when this angle is below 10°, between 30° and 40°, between 130° and 140° or near to 180°. Those color pairs of which hue planes are between 60° and 90° to each other in Coloroid color space, exhibit the least harmony content. © 2008 Wiley Periodicals, Inc. Col Res Appl, 34, 33–44, 2009.     

Experimental determination of laws of color harmony. Part 6: Numerical index system of color harmony

The numerical index system of color harmony is intended to mark a great number of color pairs, optimally any number of existing color pairs, by a number between 0 and 100. This number expresses the extent to which a color pair is being felt harmonious by the average of people and the level of harmony content it possesses. The experiments described in this article have determined the basic data necessary to create this system. The series of the experiments have been done in two stages. The first stage, in which 24 test objects were presented to the experimental subjects, was carried out twice first in 1988–1990 and again in 2004–2006. Every test set was composed of eight compositions. The number of scores, given to each of the compositions, determined the harmony content of the color pair groups, whose members are formed from the saturated colors of different hues and from the members of the grey scale. In the second stage of the experiment, these data served as references for the experimental subjects. In the second stage, there were 192 tests. In these tests, there were different numbers of compositions each formed of different color pairs. One of the members of these color pairs was the member of the saturated color of the first experiment. The second member was always of different saturation and lightness for each of the compositions, purposefully chosen to match the saturated colors. Based on the experimental scores, we obtained a color harmony surface linked to the intersections with the coordinates in the Coloroid system. The color harmony surfaces and the distances between the related intersections indicate the harmony content of the color pair. The numerical values of these distances are called the color harmony index number of the color pair. These data make the creation of a color harmony indexing system possible, expressing the color harmony content of all possible color pairs, in the color space. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012     

Experimental determination of laws of color harmony. Part 2: Harmony content of different monochrome color pairs

In 1956, we came to the decision at the Budapest Technical University to start large scale experiments on color harmony. The experiments and the processing of the experimental results have been completed in 2006, after 50 years of research work. The focal point of the experiments published in the current article has been the practical experience that the span of intervals between saturations and brightnesses of the compositions influence the harmony content of the composition, namely they determine in what extent we perceive the color composition as a harmonic one. Within the framework of experiments compositions have been shown to the participants, first those consisting of color pairs featuring the same hues and saturations but different brightnesses then those consisting of the same hues and brightnesses but different saturations. The method of experiments consisted of comparisons in pairs. There were 780 compositions prepared for the tests. The number of elementary observations during the tests comprised 544 000. It has been established that the variation of harmony content as a function of brightness‐ and saturation‐intervals could be described by a harmony function. It has been established that the variation of harmony content depending on brightness‐intervals is not, but that of depending on saturation intervals is being influenced by the hues of colors of the color pair in the composition. It has been established that in case of compositions with the maximum harmony content the interval of brightnesses of the colors making the color pair in each case gives d30V (d9Y), the interval of saturations gives d30T or is near to it. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 262–270, 2008.     

Experimental determination of the laws of color harmony. Part 4: Color preference and the color harmony content

In 1956, we decided at the Budapest University of Technology and Economics to start a large‐scale experiment on color harmony. The experiments and the processing of the experimental results have been completed in 2006. These experiments, described in this article, form a study of how much are people, participating in the experiment, influenced by their own personal color preference in judging the harmony content of a composition. These experiments have utilized the results of former (1958–1969) color preference experiments and the system of color preference indexes, which were developed by the generalization of those results. Within the framework of these experiments, conducted between 1998 and 2006 there were 24 compositions, shown to the participants, at first one by one, then in pairs and at last in groups of six. They had to assess the harmony content of the compositions and award a score on a scale between 0 and 10. Each composition possessed a specific amount of harmony content according to the rules of color space, based on the Coloroid harmony threshold and verified by former experiments. In these experiments the number of elementary observations were 135 568. The people participating in the experiment were approximately equal number of men and women, from the age group between 10 and 70 years. During processing, by using the color preference numerical indexing system, we compared the results of those experiments with the color preference of a similar age group, by using color compositions, identical to the ones used in the present experiment. We have found that the sensation of the color harmony and its intensity have a strong relation to how the observers relate to colors and also their color preferences. The sensation of color harmony is also influenced by the gender and the age of the observer. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 210–224, 2009     

Experimental determination of laws of color harmony. Part 1: Harmony content of different scales with similar hue

In 1956 we came to the decision at the Budapest Technical University to start large scale experiments on color harmony. The experiments and the processing of the experimental results have been completed in 2006, after 50 years of research work. Within the frame of the experiments 95 000 participants have carried out more than 36 million elementary observations and made elementary decisions. Only certain parts of the experimental results have been published up to now. This article starts publishing the results not published yet. Research work on color harmony carried out during these 50 years can be categorized into seven main groups. The present article deals with the group of experiments testing how much the harmony content of the scales found in different locations in various positions of the axial sections of the Coloroid color system differ from each other. Our experiments were focused to three groups: we examined the variations in the extent of harmony content in the following cases (1) scales carried by lines with different angles to the gray axis, consisting of colors having the same number of harmony intervals between them, (2) scales consisting of colors being parallel to the gray axis, featuring various saturations, having different harmony intervals between them, and (3) scales perpendicular to the gray axis, with different luminosity, having different harmony intervals between each other. The examined color scales contained six colors in each experiment. Experiments were carried out for 24 different axial sections of the Coloroid color system. After 15‐years interruption experiments were repeated; however, with compositions of different appearances. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 477–488, 2007     

Research on color harmony of building façades

In this study, the 28 primary colors and 11 complementary colors suggested by Chang et al in their investigation on building colors in Wanhua District of Taipei City were taken as color samples. The two-color combination mode was adopted to obtain 308 simulation photos, and two-color harmony was discussed from the perspective of visual evaluation using psychophysical tests. This study explored building façade color harmony in the CIELAB color space, and the relationship between the color attributes (hue, lightness, and chroma) and the color harmony, and between the differences of the color attributes and color harmony. It found that a high lightness of a building's primary color is associated with a high level of building color harmony, while the color harmony is reduced when the color falls in the green or blue sector in the CIELAB color space; a greater lightness difference between building façade colors is associated with a higher level of building color harmony, while the colors are disharmonized when they tend to the blue sector in the CIELAB color space. The contribution of this study is to summarize the principles for the application of building color harmony in urban renewal, and proposed suggestions on building color harmony in the urban renewal process.     

Color harmony in two‐piece garments

Using a categorical scale of 10 U, we have assessed color harmony in two‐piece garments (jackets‐trousers) considering a vicenarian and a quinquagenarian style. The experiment was performed by a panel of 59 Chinese observers (26 males and 33 females) with normal color vision and ages ranging 20–78 years, considering 300 color combinations for each of the two styles. For a given color combination, comparing results in the vicenarian/quinquagenarian styles for female/male observers, and observers below/above 45 years old, we found generally higher harmony scores for the vicenarian style, male observers, and observers older than 45 years. We found statistically significant differences (Welch two‐sample t test, P < 0.001) between color‐harmony results for the vicenarian and quinquagenarian styles, as well as considering the scores reported both by male/female observers and by observers below/above 45 years old. We propose a very simple lineal model fitting our current results with an average root mean square error (RMSE) of 0.70 U in our 10‐unit scale, which is below the one achieved by other complex models previously proposed, and also below the inter‐ and intra‐observer variability in our experiment. From our total experimental results, each of the five traditional color‐harmony principles (complementary hues and equal lightness, chroma, tone, and hue) was found to be valid at a low percentage (53–58% of the cases). © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 498–511, 2017     

Experimental determination of laws of color harmony part 8: Harmony content versus relative surface coverage

Abstract: It is a recognized fact, that the relative surface coverage of the colors has a great influence on the harmony content. It is an open question that, in a composition, what is the optimum ratio between the surface area coverage of the colors, for maximum harmony content of the color pairs, selected for the composition. Various theories on color harmony already tried to answer this question, based on two substantially different principles. One is built on the mechanism of color vision, while the other one founded on statistical test results. The first approach was already proven not valid; but the second one was not proven right either due to the lack of available data. Our experiments aim is to fill this gap by using 324 compositions with different color coverage, to investigate its relation to harmony content. The statistical results were summarized in graphs as well as formulated in mathematical equations. The results show that the prime factor in the measure of harmony content is the relative surface coverage of the highly saturated colors. In most cases however the 50–50% ratio of color coverage leads to maximum harmony content in a composition. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 387–398, 2014     

Complementary colors theory of color vision: Physiology,color mixture,color constancy and color perception

I describe complementary colors' physiology and functional roles in color vision, in a three‐stage theory (receptor, opponent color, and complementary color stages). 40 specific roles include the complementary structuring of: S and L cones, opponent single cells, cardinal directions, hue cycle structure, hue constancy, trichromatic color mixture, additive/subtractive primaries, two unique hues, color mixture space, uniform hue difference, lightness‐, saturation‐, and wavelength/hue‐discrimination, spectral sensitivity, chromatic adaptation, metamerism, chromatic induction, Helson‐Judd effect, colored shadows, color rendering, warm‐cool colors, brilliance, color harmony, Aristotle's flight of colors, white‐black responsivity, Helmholtz‐Kohlrausch effect, rainbows/halos/glories, dichromatism, spectral‐sharpening, and trimodality of functions (RGB peaks, CMY troughs whose complementarism adapts functions to illuminant). The 40 specific roles fall into 3 general roles: color mixture, color constancy, and color perception. Complementarism evidently structures much of the visual process. Its physiology is evident in complementarism of cones, and opponent single cells in retina, LGN, and cortex. Genetics show our first cones were S and L, which are complementary in daylight D65, giving a standard white to aid chromatic adaptation. M cone later split from L to oppose the nonspectral (red and purple) hues mixed from S+L. Response curves and wavelength peaks of cones L, S, and (S+L), M, closely resemble, and lead to, those of opponent‐color chromatic responses y, b, and r, g, a bimodal system whose summation gives spectral‐sharpened trimodal complementarism (RGB peaks, CMY troughs). Spectral sharpening demands a post‐receptoral, post‐opponent‐colors location, hence a third stage. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011     

Preference for accent and background colors in interior architecture in terms of similarity/contrast of natural color system attributes

Color combination criteria are said to entail an affective response in interior design. We investigated the color combination criteria that orient the preference of current observers, after Le Corbusier's 1931 Salubra keyboards. We explored the similarity/contrast in Natural Color System (NCS) hue, blackness, and chromaticness in 312 combinations with four colors, two backgrounds and two accent colors, coming from 43 individual colors, on the walls of a simulated interior of a bedroom from the Swiss Pavilion (Le Corbusier, 1930-1931). Participants were 644 students of architecture and interior design in Western Europe and Near East, who evaluated with a Likert scale their preference for virtual images via an online survey. Results indicate that the most preferred color combinations are those with hues closer in the color wheel, being the similarity between hues in the backgrounds more important than in the accent colors, and with NCS B30G to G as the most preferred hues. Observers preferred color compositions with blackness under 10% and similar blackness between the two background colors, together with a certain blackness contrast between these background colors and the two color accents. Similarly, observers liked color compositions with low chromaticness and low chromaticness difference among the four colors of the composition.     

An interactive method for generating harmonious color schemes

We present an interactive visualization tool for generating color schemes that can be used by both professional artists and novice designers to improve their design efficiency. The method is developed on two color harmony principles of familial factors and rhythmic spans from conventional color theories. The interactive tool makes use of these principles for users to interactively generate colors palettes containing harmonious combinations in the hue, saturation, and lightness color space in as few steps as possible. A pilot study with 20 participants has shown that this tool provides efficient workflow, color‐scheme harmony, and intuitive interaction, demonstrating the usefulness of the method. This work contributes to an artistic‐theory driven harmonious color‐scheme generation and to interactive user interfaces visualizing color relationships. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 70–78, 2014     

Influence of a holistic color interval on color harmony

This study investigates how a holistic color interval, i.e., the nondirectional color difference between a pair of colors in a CIELAB uniform color space, influences perceived color harmony. A set of 1035 test color pairs displayed on a CRT was evaluated for the degree of harmony. These test color pairs consist of pairs combined from among the selected 46 test colors evenly distributed in color space. The subjects were asked to select their three preferred colors from these 46 test colors and then to evaluate the degree of harmony of the test color combinations. The color intervals (ΔE) of each test color combination were calculated and treated as values of an independent variable. In addition, the evaluated degrees of color harmony were considered as values of a dependent variable, in which statistical analysis confirmed the relationship: the degree of harmony is a cubic function of the color interval. Moreover, the plot of this relationship allowed us to identify four color intervals: roughly corresponding to the regions of first ambiguity, similarity, second ambiguity, and contrast in Moon and Spencer's model. However, our results indicated that Moon and Spencer's principles for classifying harmonious/disharmonious regions in terms of the color interval for three color attributes—lightness, chroma and hue—may be inappropriate in predicting perceived color harmony. As for the color intervals between a pair of colors considered as a function of the three attributes, the interval for lightness may have a predominant effect on color harmony, expressed in terms of a cubic relationship. Results of the study further demonstrated that the subject's choice of colors significantly influences perceived color harmony. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 29–39, 2001     

Hue,saturation, lightness,and building exterior preference: An empirical study in Turkey comparing architects' and nonarchitects' evaluative and cognitive judgments

This study investigated architects' and nonarchitects' evaluative and cognitive judgments of color on building exteriors. Thirty architects and 30 high school teachers living in Izmir, Turkey participated in the study. The experiment had two phases. First, participants viewed eight images, in which the color of a building exterior was manipulated with hues selected from HSB (hue, saturation, and brightness) color space. Participants were then asked to rate each image on 7‐point semantic differential scales measuring preference (like–dislike), arousal (arousing–sleepy), naturalness (natural–artificial), and relaxation (relaxing–distressing). Second, participants viewed the same building in nine saturation and lightness levels for each hue and picked the most preferred lightness and saturation level for each hue. Findings showed that for a building exterior: (1) yellow and blue were the most liked colors, (2) some hues were rated as more arousing, more natural, and more relaxing over the others, (3) gender had an effect on color preference and semantic ratings of naturalness and relaxation, (4) architects and nonarchitects differed in their color preference and semantic ratings of arousal and naturalness, and (5) full bright and moderate to low saturated colors and full saturated and moderate to high bright colors were preferred more. The results have practical implications for architects and urban designers. A successful coloration of a building exterior may increase its use frequency and economical value. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 395–405, 2008     

Color combination criteria in Le Corbusier's Purist architecture based on Salubra claviers from 1931

We have carried out a new study of the color combinations selected by Le Corbusier in ‘les claviers de couleurs’ for the Salubra wallpaper company in 1931, by analyzing them in the Natural Color System, which allows us to understand the perceptive variables of colors (hue, blackness, and chromaticness) as well as their combination criteria. Regarding the perceptive variables, we have discussed the selected hue ranges in relation to other color proposals of Le Corbusier himself, and we have shown the extensive presence of earthy hues, or the noteworthy absence of other colors such as yellows, violets, black, and white. We have also analyzed the chromaticness of colors, which is generally low, and the blackness, also very limited. In relation to the combination criteria, we aim to find out the underlying order in the color combinations by studying the similarities and contrasts of their perceptive variables. We demonstrate graphically, by a navigable three‐dimensional model, and with statistical support, some principles in Le Corbusier's color preferences, such as the combination of colors with equal chromaticness, the search of some contrast in blackness, or the usual resource of contrasting cool with warm colors, something slightly different to the contrast of complementary colors. We have also discussed other compositional criteria held by Le Corbusier to use color in his Purist architecture, which are related to the position and proportion of the surfaces to be colored, the connotations associated to different hues, or the use of plain colors, among others. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 85–100, 2016     

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.     

Color characteristic of Castle District built on the hill

In this article the used of the colordynamic planning method is described and applied as an example to the façade of a building in Buda. The method of colordynamic planning consists of 3 essential parts. In the first part we decide on the limits of the color range to be used, based upon the requirements of the subject of planning. The decision on these limits is closely linked to the coordinates of the Coloroid system. In the second part the planner creates harmonic color scales from the previously selected color range. In this work he is helped by rules of the Coloroid system, based on harmony thresholds. In the third part the planner selects the color harmony combinations considered suitable by him. Following that, he finalizes the Coloroid coordinates of the proposed colors most suitable for the project. For the presentation of the colordynamic planning method, based on the Coloroid system, we use a real database of a colordynamic plan, which was awarded the first prize in an international competition.     

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     

The impact of signboard-building color combinations on color harmony and legibility

The aim of this study was to investigate the impact of signboard-building color combinations on color harmony and legibility. Two hundred and three participants rated 54 signboard-building color combinations against two scales of color harmony and legibility. In this article, the terms “brick,” “stone,” and “glass” refer to three types of building exteriors used in the experiment (ie, brick masonry, greystone, and curtain walls, respectively). Major findings are as follows: (a) there was a positive linear correlation between color harmony and legibility in all three types of building exteriors, (b) the type of building exterior affected the color harmony and legibility of signboard colors, (c) no hue-related patterns were observed, (d) the effects of chroma differences on color harmony were weak and the effects of chroma differences on legibility were moderate, (e) the effects of lightness differences on color harmony and legibility were strong in brick, but the effects of lightness differences were weak in stone and glass, (f) white color combinations (ie, color pairs including white signboards) turned out to be the most harmonious and legible, and (g) color combinations of light signboards and dark buildings (negative polarity) were rated most harmonious and legible, with the exception of vivid red (positive polarity). The findings of this study provide insight into the characteristics of harmonious and legible colors in the context of signboard design.     

Effects of hue,saturation, and brightness on preference

A study was done to investigate preference responses for foreground–background color relationships. To do this, 123 university undergraduates in Ankara, Turkey, were asked to view eight background colors selected from HSB color space on which color squares of differing hues, saturations, and brightnesses were presented. Subjects were asked to show the color square they preferred on the presented background color. Findings showed that colors having maximum saturation and brightness were most preferred. Blue was the most preferred hue regardless of background. The findings for preferences for foreground–background color relationships are also included in this article. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 199–207, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10051