In colorimetry, the Munsell color system is a color space that specifies colors based on three color dimensions: hue, value (lightness), and chroma (color purity). It was produced by Professor Albert H. Munsell in the first decade in the twentieth century and adopted through the USDA since the official color system for soil research within the 1930s.
Several earlier color order systems had placed colors right into a three-dimensional color solid of merely one form or another, but Munsell was the first to separate hue, value, and chroma into perceptually uniform and independent dimensions, and the man was the first one to systematically illustrate the colors in three-dimensional space. Munsell’s system, specially the later renotations, will depend on rigorous measurements of human subjects’ visual responses to color, putting it with a firm experimental scientific basis. For this reason basis in human visual perception, Munsell’s system has outlasted its contemporary color models, despite the fact that it has been superseded for a few uses by models including CIELAB (L*a*b*) and CIECAM02, it is actually still in wide use today.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 learned that if hue, value, and chroma would be kept perceptually uniform, achievable surface colors could not really forced in to a regular shape.
Three-dimensional representation of your 1943 Munsell renotations. Spot the irregularity in the shape when compared to Munsell’s earlier color sphere, at left.
The system is made up of three independent dimensions which is often represented cylindrically in three dimensions as 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 colors along these dimensions if you take measurements of human visual responses. In each dimension, Munsell colors are as near to perceptually uniform since he might make them, that makes the resulting shape quite irregular. As Munsell explains:
Want to fit a chosen contour, like the pyramid, cone, cylinder or cube, along with an absence of 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 up into five principal hues: Red, Yellow, Green, Blue, and Purple, as well as 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. All these 10 steps, with the named hue given number 5, will then be broken into 10 sub-steps, to ensure that 100 hues receive integer values. In reality, 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 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 along the color solid, from black (value ) at the end, to white (value 10) on the top.Neutral grays lie along 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 hold 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 centre of each slice, represents the “purity” of the color (related to saturation), with lower chroma being less pure (more washed out, as with pastels). Keep in mind that there is absolutely no intrinsic upper limit to chroma. Different aspects of the hue space have different maximal chroma coordinates. For example 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 triggered a variety of possible chroma levels-around the high 30s for many hue-value combinations (though it is not easy or impossible to create physical objects in colors of these high chromas, and they should not be reproduced on current computer displays). Vivid solid colors happen to be in the range 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, as much as 5Y 8.5/14). However, they are certainly not reproducible inside the sRGB color space, which has a limited color gamut created to match that from televisions and computer displays. Note also that there 85dexupky no samples for values (pure black) and 10 (pure white), which are theoretical limits not reachable in pigment, with out printed examples of value 1..
One is fully specified by listing the 3 numbers for hue, value, and chroma in that order. For example, a purple of medium lightness and fairly saturated could be 5P 5/10 with 5P meaning the hue in the center of the purple hue band, 5/ meaning medium value (lightness), along with a chroma of 10 (see swatch).
The thought of using a three-dimensional color solid to represent all colors was made during the 18th and 19th centuries. A number of different shapes for such a solid were proposed, including: a double triangular pyramid by Tobias Mayer in 1758, one particular 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 several hues. But them all remained either purely theoretical or encountered practical problems in accommodating all colors. Furthermore, none was based on any rigorous scientific measurement of human vision; before Munsell, the relationship between hue, value, and chroma was not understood.
Albert Munsell, an artist and professor of art on the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to create a “rational way to describe color” that could use decimal notation rather than color names (which he felt were “foolish” and “misleading”), that he could use to teach his students about color. He first started work on the device in 1898 and published it completely form in the Color Notation in 1905.
The initial embodiment of your system (the 1905 Atlas) had some deficiencies as a physical representation of your theoretical system. These were improved significantly inside the 1929 Munsell Book of Color and through a thorough group of experiments done by the Optical Society of America within the 1940s leading to the notations (sample definitions) for the modern Munsell Book of Color. Though several replacements for the Munsell system are already invented, building on Munsell’s foundational ideas-including the Optical Society of America’s Uniform Color Scales, and the International Commission on Illumination’s CIELAB and CIECAM02 color models-the Munsell method is still traditionally used, by, amongst others, ANSI to define skin and hair colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during selecting shades for dental restorations, and breweries for matching beer colors.