The coloroid color system

Developed over two decades at the Technical University, Budapest, the Coloroid color system is an aesthetically uniform system, in which scales of hue, saturation, and lightness appear to change uniformly over their entire length, when viewed as a whole. This is not the same as perceptually uniform in the sense of even intervals of small color differences. This article discusses the concepts and derivation of the Coloroid system, relates it to the Munsell and Ostwald systems, and derives the relations of its coordinates to those of the CIE XYZ system.     

The chevreul color system

Chevreul wished to represent in his color system every modification of color, including not only the modifications we observe from pigment mixtures but also those modifications in color that we observe in nature. The latter include the various gradations of light and shade on the surface color of objects which light enables us to perceive. A review and clarification of his color system reveals a logical correlation between these phenomena and the various scales in his color system. Studying these scales and understanding the concepts they represent can be very helpful to painters who wish to represent in their paintings objects in space and light in a naturalistic manner.     

The munsell color system in fundamental color space

The Munsell color system is investigated as a structure in fundamental color space. The entire collection of samples from the 1929 Munsell Book of Color is mapped into fundamental color space and surfaces of constant hue, value, and chroma are identified. An algorithm, based on these surfaces, is presented for estimating the Munsell specification of an arbitrary reflectance curve.     

好色之徒，给你点颜色看看

我们在居家装修时或者选择玻璃工艺品以及工艺玻璃装饰家时，往往忽略了色彩的作用，下面几招将成就你为“好色之徒”。     

The story of the DIN color system

The DIN Color Chart rests on a development of more than 40 years. It belongs to a group of color order systems that attempt to show equal distances in defined color series. The choice of hue, saturation, and darkness degree as a function of relative luminance factor, and the extended use of colorimetry for interpolations and extrapolations are characteristic elements of this color system. As results of the nature of the colorimetric definitions, several compromises give rise to deviations of the color series from purely psychological ordering. The main aim is technical application in close connection with colorimetry.     

Interrelation of the natural color system and the munsell color order system

The CIE tristimulus values of the aim points of the Natural Color System (NCS) were converted to Munsell notations using a computer program. The values so converted were those from the four elementary hues R, Y, G, and B, and the intervening hues for which full pages of colors exist in the NCS Colour Atlas. The resulting notations were plotted on Munsell Value-Chroma and Hue-Chroma charts and analyzed for several features of interest, for example the locations of the points with 100% chromaticness and the relative spacing of the hue circles. Analytical equations are presented relating Munsell Chroma and NCS chromaticness, and Munsell Value and NCS blackness, for both achromatic and chromatic samples. Such analytical relationships could not be derived between the hues of the two systems, since a relatively wide range of hue in either system corresponds to constant hue in the other. This range appears to include both systematic and random components that must be removed before analytical relations between the two hues can be derived.     

建立高效的零售店调色系统

阐述了建立一套高效零售店调色系统的必要性、所需要的资源和需要进行的工作,详细讲述了零售店调色系统各部件的要求,结合中国涂料市场的现状就建立适合中国市场的零售店调色系统进行了探讨。     

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).     

Ultrapure water system design considerations

Although ultrapure water quality requirements vary slightly from one industry to another, it is possible to design a basic generic system that, with slight modifications, will meet virtually any specific requirement. As usual, design, construction and operation involve compromises between good engineering practice and economics. Hopefully, this paper has provided some insight into these areas.     

Cesia: A system of visual signs complementing color

Color theory has been worked up by some researchers in order to consider factors such as transparence, brightness, opacity, etc., but no color order system has been devised to include these variables in addition to the usual three. This work proposes to treat these factors as theoretically separate from color (even if they are related with it), developing an order system for them. When it is taken parallel to color, this system helps to describe all the visual perceptions produced by light stimuli.     

乳胶漆电脑调色系统的建立

描述了电脑调色系统的组成、电脑配色基本原理、电脑调色对色浆的要求,介绍了基础漆的建立(包括颜料体积浓度设计,颜填料、乳液、润湿分散剂、增稠剂等原料的选择),给出了颜料絮凝度及着色力的检测方法。     

焦炭塔进料短管内加导流板的可行性分析

焦炭塔进料短管内加装导流板后可能影响装置的正常生产,文章针对可能造成的各种不利影响进行了的计算分析,确认进料短管内加装导流板这一改造措施安全可行。     

The metamerism potentiality of a color recipe

The weighted spectrophotometric color matching method with the optimum weighting to the spectrophotometric equations in each particular wavelength proportional to the viewing condition is applied for minimizing the color difference of instrumental color formulation of textile materials. The work is based on the one‐constant Kubelka–Munk theory. The sensitivity of a recipe to small perturbation of deviation between the reflectance of target and matched samples in the visible spectrum is determined as the metamerism potentiality of proposed recipe. Its correlation with metamerism index was also studied for some metameric pairs. Metamerism potentialities are also appraised under several light sources by using equilibrate matching strategy. The results show that the outputs of colorimetric color matching are exactly identical with the weighted spectrophotometic match under the same viewing condition. According to the numerical results for matching of 58 target samples, there is a good statistical correlation between metamerism indices and the metamerism potentialities of each recipe. Our results show that the quantitative value of the metamerism potentiality of each recipe can reasonably predict the metamerism indices of applied formulation. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 483–490, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20261     

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     

The non-adiabatic tubular reactor: Stability considerations

This paper is a continuation of four previous ones in this journal ^{(1, 2, 3, 4)} and is involved with the transient and stability behavior of a non-adiabatic unpacked tubular reactor. The steady states found earlier are tested for stability both by computing transient profiles and by computing the eigenvalues of the appropriate linearized problem. It is found in all cases that the two computations predict the proper stability behavior. It is shown that in some cases all steady states for a given set of parameters may be unstable and that a unique steady state may give rise to an oscillatory system.     

电脑测配色系统在实色涂料中的应用

简要介绍电脑测配色系统中的硬件和软件系统中的概念,详细阐述了应用于atacolor电脑测配色系统建立配色数据库的过程,及影响电脑测配色系统在实色涂料中颜色精度的因素。     

Atdn: Toward a uniform color space

To derive a uniform chromaticity space for small color differences, we applied compressive intensity-response functions of the form ρ = Iⁿ/(σ + Iⁿ) to each of the four color signals from the T (red vs. green) and D (blue vs. yellow) mechanisms of the ATD vector model for color vision. The values of σ and n for each response were optimized by computer iteration to provide reasonably uniform color spaces (ATDN) for describing the color-discrimination data of MacAdam [J. Opt. Soc. Am. 32 , 246-274 (1942)] and Pointer [J. Opt. Soc. Am. 64 , 750–759 (1974)]. To determine how well ATDN accounts for large color differences, we transformed the coordinates of the Munsell renotation system to ATDN space. Origin-bound radial lines and origin-centered circles in ATDN are about equivalent to those of CIELAB in approximating iso-hue and iso-sat-uration contours of the Munsell system. A computer program written in BASIC that can be used to transform 1931 CIE X, Y, Z values to points in ATDN space is included as an appendix.     

Size effect of color patches for their color appearance with foggy goggles simulating cloudy crystalline lens of elderly people

The cataract eyes can be characterized by three elements; luminance, spectral distribution, and scatter, which are perceived as brightness, color, and fogginess, respectively. Change of any of the three elements may affect visual performance. The foggy element, which refers to the perception associated with a change in the optical scatter of the crystalline lens, causes deterioration of the visual acuity, pattern perception, and an uncomfortable foggy appearance over the visual field. Moreover, it also affects the ability to discriminate and perceive colors. The environmental light coming to the eyes from all directions overlay the retinal image of a color patch and causes to reduce the color purity of the image. Color desaturation of the patch takes place. In this article, it is suggested that if the patch is enlarged in size the environmental light coming from the immediate surroundings of the patch is replaced by the color of the patch itself reducing the desaturation of the patch and leading to a greater perception of the original patch color. Three foggy filters were made to fit goggles and subjects, while wearing the goggles, were allowed to observe red, yellow, green, and blue color patches of six different sizes under four different illuminance levels to control the strength of the environmental light. When the color patch size was small as 0.7° of visual angle the chromaticness perceived on each of the color patches was extremely small under an environmental light of 300 lx, but increased rapidly as the color patch size increased to 5.9° of visual angle. When the environmental light was reduced to 10 lx, the degree of apparent color desaturation was markedly reduced to only a slight amount. The haze value of the foggy filters was also found to be significant with the larger the haze value the stronger the desaturation of the test color patches. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 351–358, 2009