Munsell Color Chips Research Articles

Color‐discrimination perimetry

AbstractColor‐discrimination perimetry was performed using Munsell color chips to determine how far from the fovea specific color differences would be just‐noticeably different. The results show that color‐discrimination limits were larger in the red‐to‐purple and the blue‐to‐green regions of the color circle than in the purple‐to‐blue, the green‐to‐yellow, and the yellow‐to‐red regions. Achromatic color‐discrimination limits went further into the periphery than did chromatic limits. We also performed color‐naming experiments at the fovea and in the periphery (30° nasal). Our results are reasonably well accounted for by the deuteranopic tendencies in the periphery of the retina.

Criteria of Color Contrast in a Nematic Liquid Crystal Display

Abstract Color contrast in a nematic liquid crystal display is defined experimentally. Liquid crystal cell shows a positive dielectric anisotropy and is operated in a tunable birefringence mode. Munsell color chips used as background color. Colorimetric data are shown in the 1976 CIE (L*, a*, b*) color scale. First, a predict equation of color shift induced by background color is derived and shows a good agreement with the result of experiment. Second, criterial of color contrast is established by taking into account the color shift. The values of criteria nearly coincide with that of psychophysical experiment by single-stimulur method, and the validity of criteria is confirmed.

Color shift induced by background color in a nematic liquid crystal display

Color shift induced by background color in a nematic liquid crystal display is investigated experimentally. A liquid crystal cell shows a positive dielectric anisotropy and is operated in a tunable birefringence mode. Munsell color chips 5R-, 5G-, 5B-5/6, and N-5 are used as background color. Colorimetric data are shown in the 1976 CIE (L*, a*, b*) color scale. A predict equation based on induction theory is found to apply with fair success to the observations of each of the five observers.

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

AbstractForty‐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.

Relationship between Color Rendering Indices and Shifts in Munsell Space

A method is described for resolving the color shifts associated with the special color rendering indices into changes in Munsell hue, chroma, and value. Spectral reflectance distributions of Munsell color chips corresponding to the CIE test colors and their neighboring colors were measured. CIE 1964 uniform color coordinates were then calculated using these reflectance spectra and spectral power distributions of a range of reference illuminants. By least squares fitting of the data, a set of equations were derived that can be used for estimating color shifts in Munsell space. The method is applied to several light sources.

The size-color illusion.

Slides were made from Munsell color chips in three sizes, four hues, and two chromas; all had the same intensity. A direct-comparisons, forced-choice procedure was used with 100 male and female volunteers from psychology courses. When pairs of slides had the same size and chroma, the order of decreasing apparent size was red-purple, yellow-red, purple-blue, and green. At chroma/8, all comparisons were significant except yellow-red over purple-blue. At chroma/4, the same order was found, but the effect was not pronounced. When pairs were made up of identical hues but different chromas, the square with chroma/4 (less saturation) appeared significantly larger.

Some factors in effective communication.

To determine the number of dimensions needed to account for behaviour in an instrumental communication task, verbal descriptions of 40 Munsell colour chips were elicited from four subjects. Later these same subjects tried to identify the chips on the basis of the descriptions. Every subject served both as speaker and listener for every other subject, including himself. Coombs' non-metric multi-dimensional scaling technique was used to analyse the 16 speaker-listener pairs, rank ordered for effectiveness of communication and two, possibly three, dimensions were found: (1) listening skill ; (2) skill in describing colours, both for self and other listeners ; and (3) response similarity with other subjects, as measured either by the degree of lexical similarity in the composition of verbal descriptions or by the degree of overlap of choices made in the identification of colour chips. These results were interpreted as evidence against the existence of a generalized uni-dimensional communication skill.

Dependency of the spectral reflectance curves of the Munsell color chips

The spectral reflectance curves of 433 chips in the Munsell Book of Color have been found to depend on only three components which account for 99.18% of the variance. It is suggested that this three-component dependency may be a characteristic of all organic pigments, including those in the retina, and thus explain the trichromatic nature of color vision.

Memory colors of familiar objects.

The memory colors of ten familiar, naturally occurring objects have been determined. Fifty observers chose their memory colors from an array of 931 Munsell color chips. The variability of the judgments is shown and their means are compared with the average chromaticities of the corresponding natural objects. The ten mean memory colors were all significantly different from the natural colors. Each memory color tended to be more characteristic of the dominant chromatic attribute of the object in question; grass was more green, bricks more red, etc. In most cases, saturation and lightness increased in memory.

Color Identification as a Function of Extended Practice*

The use of color as a coding device has been limited in some important applications because a practical maximum of only about 15 absolutely identifiable colors have been found experimentally. This investigation was undertaken to determine whether or not substantial improvement in color identification could be obtained as a result of extended practice. One subject practiced on Munsell color chips for about five months. Performance improved continuously, and at the end of the practice period the subject was able to identify 50 colors with almost perfect accuracy. However, errors increased markedly during three months of no practice immediately following the training period.