In colorimetry, the Munsell color method is a color space that specifies colors depending on three color dimensions: hue, value (lightness), and chroma (color purity). It was created by Professor Albert H. Munsell inside the first decade in the 20th century and adopted by the USDA since the official color system for soil research in the 1930s.
Several earlier color order systems had placed colors in a three-dimensional color solid of one form or another, but Munsell was the first one to separate hue, value, and chroma into perceptually uniform and independent dimensions, and the man was the first one to systematically illustrate the shades in three-dimensional space. Munsell’s system, especially the later renotations, is dependant on rigorous measurements of human subjects’ visual responses to color, putting it on a firm experimental scientific basis. Due to this basis in human visual perception, Munsell’s system has outlasted its contemporary color models, despite the fact that this has been superseded for a few uses by models for example CIELAB (L*a*b*) and CIECAM02, it can be still in wide use today.
Munsell’s color sphere, 1900. Later, munsell soil color chart learned that if hue, value, and chroma were to be kept perceptually uniform, achievable surface colors could not forced right into a regular shape.
Three-dimensional representation of your 1943 Munsell renotations. Spot the irregularity from the shape when compared with Munsell’s earlier color sphere, at left.
The machine is made up of three independent dimensions which is often represented cylindrically in three dimensions being an irregular color solid: hue, measured by degrees around horizontal circles; chroma, measured radially outward from the neutral (gray) vertical axis; and value, measured vertically from (black) to 10 (white). Munsell determined the spacing of colors along these dimensions through taking measurements of human visual responses. In each dimension, Munsell colors are as close to perceptually uniform while he may make them, making the resulting shape quite irregular. As Munsell explains:
Desire to fit a chosen contour, including the pyramid, cone, cylinder or cube, along with not enough proper tests, has resulted in many distorted statements of color relations, plus it becomes evident, when physical measurement of pigment values and chromas is studied, that no regular contour will serve.
-?Albert H. Munsell, “A Pigment Color System and Notation”
Each horizontal circle Munsell split into five principal hues: Red, Yellow, Green, Blue, and Purple, in addition to 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. Each of these 10 steps, together with the named hue given number 5, will be broken into 10 sub-steps, to ensure 100 hues are shown integer values. In practice, color charts conventionally specify 40 hues, in increments of 2.5, progressing regarding example 10R to 2.5YR.
Two colors of equal value and chroma, on opposite sides of a hue circle, are complementary colors, and mix additively on the neutral gray of the identical value. The diagram below shows 40 evenly spaced Munsell hues, with complements vertically aligned.
Value, or lightness, varies vertically across the color solid, from black (value ) at the end, to white (value 10) at the very top.Neutral grays lie across the vertical axis between monochrome.
Several color solids before Munsell’s plotted luminosity from black at the base to white at the top, by using a gray gradient between them, however these systems neglected to help keep perceptual lightness constant across horizontal slices. Instead, they plotted fully saturated yellow (light), and fully saturated blue and purple (dark) along the equator.
Chroma, measured radially from the center of each slice, represents the “purity” of the color (relevant to saturation), with lower chroma being less pure (more washed out, like pastels). Remember that there is no intrinsic upper limit to chroma. Different aspects of the hue space have different maximal chroma coordinates. As an illustration light yellow colors have significantly more potential chroma than light purples, due to nature in the eye along with the physics of color stimuli. This resulted in a variety of possible chroma levels-as much as the top 30s for many hue-value combinations (though it is sometimes complicated or impossible to help make physical objects in colors of the high chromas, and they cannot be reproduced on current computer displays). Vivid solid colors will be in all the different approximately 8.
Be aware that the Munsell Book of Color contains more color samples than this chart for both 5PB and 5Y (particularly bright yellows, up to 5Y 8.5/14). However, they are not reproducible inside the sRGB color space, that features a limited color gamut designed to match that of televisions and computer displays. Note also that there 85dexupky no samples for values (pure black) and 10 (pure white), that happen to be theoretical limits not reachable in pigment, with no printed samples of value 1..
One is fully specified by listing the three numbers for hue, value, and chroma in this order. As an example, a purple of medium lightness and fairly saturated can be 5P 5/10 with 5P meaning the hue in the midst of the purple hue band, 5/ meaning medium value (lightness), along with a chroma of 10 (see swatch).
The thought of by using a three-dimensional color solid to represent all colors was designed throughout the 18th and 19th centuries. A number of different shapes for this kind of solid were proposed, including: a double triangular pyramid by Tobias Mayer in 1758, a single triangular pyramid by Johann Heinrich Lambert in 1772, a sphere by Philipp Otto Runge in 1810, a hemisphere by Michel Eugène Chevreul in 1839, a cone by Hermann von Helmholtz in 1860, a tilted cube by William Benson in 1868, as well as a slanted double cone by August Kirschmann in 1895. These systems became progressively modern-day, with Kirschmann’s even recognizing the main difference in value between bright colors of various hues. But all of them remained either purely theoretical or encountered practical problems in accommodating all colors. Furthermore, none was based upon any rigorous scientific measurement of human vision; before Munsell, the connection between hue, value, and chroma was not understood.
Albert Munsell, an artist and professor of art at the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to generate a “rational method to describe color” that will use decimal notation as an alternative to color names (which he felt were “foolish” and “misleading”), that he could use to train his students about color. He first started work towards the machine in 1898 and published it entirely form in the Color Notation in 1905.
The first embodiment of your system (the 1905 Atlas) had some deficiencies as a physical representation from the theoretical system. They were improved significantly in the 1929 Munsell Book of Color and thru a comprehensive combination of experiments performed by the Optical Society of America in the 1940s resulting in the notations (sample definitions) for the modern Munsell Book of Color. Though several replacements for your Munsell system have already been invented, building on Munsell’s foundational ideas-for example the Optical Society of America’s Uniform Color Scales, along with the International Commission on Illumination’s CIELAB and CIECAM02 color models-the Munsell method is still widely used, by, and others, ANSI to define hair and skin colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during your selection of shades for dental restorations, and breweries for matching beer colors.