In colorimetry, the Munsell color system is one space that specifies colors based upon three color dimensions: hue, value (lightness), and chroma (color purity). It was developed by Professor Albert H. Munsell inside the first decade in the 20th century and adopted with the USDA as the official color system for soil research inside the 1930s.
Several earlier color order systems had placed colors into a three-dimensional color solid of one form or another, but Munsell was the first to separate hue, value, and chroma into perceptually uniform and independent dimensions, and that he was the first to systematically illustrate the colors in three-dimensional space. Munsell’s system, in particular the later renotations, is dependant on rigorous measurements of human subjects’ visual responses to color, putting it over a firm experimental scientific basis. Because of this basis in human visual perception, Munsell’s system has outlasted its contemporary color models, even though this has been superseded for some uses by models including CIELAB (L*a*b*) and CIECAM02, it is actually still in wide use today.
Munsell’s color sphere, 1900. Later, munsell soil color chart discovered that if hue, value, and chroma would be kept perceptually uniform, achievable surface colors could not really forced right into a regular shape.
Three-dimensional representation of the 1943 Munsell renotations. See the irregularity of your shape in comparison with Munsell’s earlier color sphere, at left.
The machine contains three independent dimensions that may be represented cylindrically in three dimensions being an irregular color solid: hue, measured by degrees around horizontal circles; chroma, measured radially outward through the neutral (gray) vertical axis; and value, measured vertically from (black) to 10 (white). Munsell determined the spacing of colours along these dimensions by using measurements of human visual responses. In each dimension, Munsell colors are as near to perceptually uniform as he could make them, which makes the resulting shape quite irregular. As Munsell explains:
Want to fit a chosen contour, such as the pyramid, cone, cylinder or cube, coupled with not enough proper tests, has triggered 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 divided into five principal hues: Red, Yellow, Green, Blue, and Purple, together with 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. All these 10 steps, with the named hue given number 5, is then broken into 10 sub-steps, so that 100 hues are given integer values. In practice, color charts conventionally specify 40 hues, in increments of 2.5, progressing concerning example 10R to 2.5YR.
Two colors of equal value and chroma, on opposite sides of the hue circle, are complementary colors, and mix additively to the neutral gray of the same 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 ) in the bottom, to white (value 10) at the top.Neutral grays lie along the vertical axis between white and black.
Several color solids before Munsell’s plotted luminosity from black at the base to white on top, having a gray gradient between them, however, these systems neglected to maintain perceptual lightness constant across horizontal slices. Instead, they plotted fully saturated yellow (light), and fully saturated blue and purple (dark) over the equator.
Chroma, measured radially from the core of each slice, represents the “purity” of a color (linked to saturation), with lower chroma being less pure (more washed out, like in pastels). Note that there is absolutely no intrinsic upper limit to chroma. Different parts of the color space have different maximal chroma coordinates. As an illustration light yellow colors have considerably more potential chroma than light purples, due to the nature of the eye as well as the physics of color stimuli. This resulted in a wide range of possible chroma levels-as much as our prime 30s for a few hue-value combinations (though it is not easy or impossible to create physical objects in colors of those high chromas, and they also should not be reproduced on current computer displays). Vivid solid colors will be in the range of approximately 8.
Remember that the Munsell Book of Color contains more color samples than this chart both for 5PB and 5Y (particularly bright yellows, around 5Y 8.5/14). However, they are not reproducible within the sRGB color space, that features a limited color gamut created to match that relating to televisions and computer displays. Note also that there 85dexupky no samples for values (pure black) and 10 (pure white), which can be theoretical limits not reachable in pigment, with out printed examples of value 1..
A color is fully specified by listing three of the numbers for hue, value, and chroma in this order. For example, a purple of medium lightness and fairly saturated would be 5P 5/10 with 5P meaning colour in the midst of the purple hue band, 5/ meaning medium value (lightness), along with a chroma of 10 (see swatch).
The notion of by using a three-dimensional color solid to represent all colors was created during the 18th and 19th centuries. Many 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, and a slanted double cone by August Kirschmann in 1895. These systems became progressively more sophisticated, with Kirschmann’s even recognizing the real difference in value between bright colors of numerous hues. But them all remained either purely theoretical or encountered practical problems in accommodating all colors. Furthermore, none was according to any rigorous scientific measurement of human vision; before Munsell, the connection 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 method to describe color” that could use decimal notation as an alternative to color names (that he felt were “foolish” and “misleading”), which he could use to teach his students about color. He first started work on the machine in 1898 and published it entirely form inside a Color Notation in 1905.
The initial embodiment of your system (the 1905 Atlas) had some deficiencies like a physical representation of the theoretical system. They were improved significantly in the 1929 Munsell Book of Color and through a comprehensive group of experiments done by the Optical Society of America within the 1940s resulting in the notations (sample definitions) for your modern Munsell Book of Color. Though several replacements to the Munsell system are already invented, building on Munsell’s foundational ideas-like the Optical Society of America’s Uniform Color Scales, as well as the International Commission on Illumination’s CIELAB and CIECAM02 color models-the Munsell method is still popular, by, among others, ANSI to define hair and skin colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during the selection of shades for dental restorations, and breweries for matching beer colors.