In colorimetry, the Munsell color system is a color space that specifies colors according to three color dimensions: hue, value (lightness), and chroma (color purity). It was actually made by Professor Albert H. Munsell in the first decade of the 20th century and adopted from the USDA as being the official color system for soil research from the 1930s.
Several earlier color order systems had placed colors in to 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 then he was the first to systematically illustrate the shades in three-dimensional space. Munsell’s system, specially the later renotations, is based on rigorous measurements of human subjects’ visual responses to color, putting it with a firm experimental scientific basis. Because of this basis in human visual perception, Munsell’s system has outlasted its contemporary color models, despite the fact that it has been superseded for many uses by models like CIELAB (L*a*b*) and CIECAM02, it really is still in wide use today.
Munsell’s color sphere, 1900. Later, munsell soil color chart found out that if hue, value, and chroma would be kept perceptually uniform, achievable surface colors could stop being forced in to a regular shape.
Three-dimensional representation of the 1943 Munsell renotations. Notice the irregularity of your shape when compared to Munsell’s earlier color sphere, at left.
The system is made up of three independent dimensions which can be represented cylindrically in three dimensions being an irregular color solid: hue, measured by degrees around horizontal circles; chroma, measured radially outward from your neutral (gray) vertical axis; and value, measured vertically from (black) to 10 (white). Munsell determined the spacing of colours along these dimensions by taking measurements of human visual responses. In each dimension, Munsell colors are as near to perceptually uniform since he could make them, making the resulting shape quite irregular. As Munsell explains:
Want to fit a chosen contour, such as the pyramid, cone, cylinder or cube, coupled with too little proper tests, has resulted in many distorted statements of color relations, and yes 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 up into five principal hues: Red, Yellow, Green, Blue, and Purple, in addition to 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. Every one of these 10 steps, using the named hue given number 5, is then broken into 10 sub-steps, to ensure that 100 hues are given 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 your hue circle, are complementary colors, and mix additively to 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 down the color solid, from black (value ) at the bottom, to white (value 10) towards the top.Neutral grays lie over the vertical axis between white and black.
Several color solids before Munsell’s plotted luminosity from black at the base to white on the top, with a gray gradient between the two, but these systems neglected to 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 core of each slice, represents the “purity” of any color (related to saturation), with lower chroma being less pure (more washed out, like in pastels). Remember that there is absolutely no intrinsic upper limit to chroma. Different aspects of the color space have different maximal chroma coordinates. For instance light yellow colors have significantly more potential chroma than light purples, as a result of nature from the eye and the physics of color stimuli. This generated an array of possible chroma levels-approximately the top 30s for a few hue-value combinations (though it is difficult or impossible to create physical objects in colors of the high chromas, and they also cannot be reproduced on current computer displays). Vivid solid colors happen to be in the plethora of approximately 8.
Note that the Munsell Book of Color contains more color samples than this chart both for 5PB and 5Y (particularly bright yellows, approximately 5Y 8.5/14). However, they are not reproducible from the sRGB color space, that has a limited color gamut built to match that relating to televisions and computer displays. Note as well that there 85dexupky no samples for values (pure black) and 10 (pure white), that happen to be theoretical limits not reachable in pigment, with out printed samples of value 1..
One is fully specified by listing three of the numbers for hue, value, and chroma because order. For example, a purple of medium lightness and fairly saturated will be 5P 5/10 with 5P meaning the hue in the midst of the purple hue band, 5/ meaning medium value (lightness), and a chroma of 10 (see swatch).
The idea of using a three-dimensional color solid to represent all colors was designed through the 18th and 19th centuries. Several different shapes for this type 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, plus a slanted double cone by August Kirschmann in 1895. These systems became progressively more sophisticated, with Kirschmann’s even recognizing the visible difference in value between bright colors of various hues. But them all remained either purely theoretical or encountered practical problems in accommodating all colors. Furthermore, none was depending on any rigorous scientific measurement of human vision; before Munsell, the relationship between hue, value, and chroma had not been understood.
Albert Munsell, an artist and professor of art with the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to make a “rational strategy to describe color” that will use decimal notation as opposed to color names (that he felt were “foolish” and “misleading”), which he can use to teach his students about color. He first started focus on the program in 1898 and published it completely form in the Color Notation in 1905.
The initial embodiment of the system (the 1905 Atlas) had some deficiencies as a physical representation in the theoretical system. These were improved significantly from the 1929 Munsell Book of Color and through a comprehensive number of experiments carried out by the Optical Society of America in the 1940s causing the notations (sample definitions) to the modern Munsell Book of Color. Though several replacements for that Munsell system have already been invented, building on Munsell’s foundational ideas-like the Optical Society of America’s Uniform Color Scales, and also the International Commission on Illumination’s CIELAB and CIECAM02 color models-the Munsell system is still popular, by, amongst others, ANSI to define hair and skin colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during picking shades for dental restorations, and breweries for matching beer colors.