In colorimetry, the Munsell color system is a color space that specifies colors based upon three color dimensions: hue, value (lightness), and chroma (color purity). It had been developed by Professor Albert H. Munsell in the first decade of the 20th century and adopted with the USDA as being 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 just one form or any other, but Munsell was the first one to separate hue, value, and chroma into perceptually uniform and independent dimensions, and then he was the first one to systematically illustrate the colours 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in human visual perception, Munsell’s system has outlasted its contemporary color models, and even though this has been superseded for many uses by models like CIELAB (L*a*b*) and CIECAM02, it is actually still in wide use today.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 were to be kept perceptually uniform, achievable surface colors could not be forced right into a regular shape.
Three-dimensional representation from the 1943 Munsell renotations. Notice the irregularity of your shape in comparison to Munsell’s earlier color sphere, at left.
The program consists of three independent dimensions that may be represented cylindrically in three dimensions for 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 colours along these dimensions by using measurements of human visual responses. In each dimension, Munsell colors are as near to perceptually uniform because he might make them, making the resulting shape quite irregular. As Munsell explains:
Need to fit a chosen contour, like the pyramid, cone, cylinder or cube, along with too little proper tests, has generated many distorted statements of color relations, and 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 provided integer values. In practice, color charts conventionally specify 40 hues, in increments of 2.5, progressing in terms of 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 on the neutral gray the exact same 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 ) towards the bottom, to white (value 10) towards the top.Neutral grays lie along the vertical axis between white and black.
Several color solids before Munsell’s plotted luminosity from black on the bottom to white on the top, with a gray gradient between them, but 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 (relevant to saturation), with lower chroma being less pure (more washed out, as in pastels). Keep in mind that there is not any intrinsic upper limit to chroma. Different areas of colour space have different maximal chroma coordinates. For example light yellow colors have considerably more potential chroma than light purples, due to the nature in the eye and also the physics of color stimuli. This triggered a wide array of possible chroma levels-up to the top 30s for many hue-value combinations (though it is difficult or impossible to make physical objects in colors of such high chromas, and they also cannot be reproduced on current computer displays). Vivid solid colors will be in all the different approximately 8.
Remember that the Munsell Book of Color contains more color samples than this chart for 5PB and 5Y (particularly bright yellows, up to 5Y 8.5/14). However, they are not reproducible within the sRGB color space, with a limited color gamut designed to match those of televisions and computer displays. Note as well that there 85dexupky no samples for values (pure black) and 10 (pure white), that are theoretical limits not reachable in pigment, and no printed examples of value 1..
One is fully specified by listing three of the numbers for hue, value, and chroma for the reason that order. As an example, a purple of medium lightness and fairly saturated can be 5P 5/10 with 5P meaning colour in the middle of the purple hue band, 5/ meaning medium value (lightness), along with a chroma of 10 (see swatch).
The concept of utilizing a three-dimensional color solid to represent all colors was designed during the 18th and 19th centuries. Many different shapes for such a solid were proposed, including: a double triangular pyramid by Tobias Mayer in 1758, just one 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 several hues. But these 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 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 method to describe color” that might use decimal notation as an alternative to color names (that he felt were “foolish” and “misleading”), which he could use to show his students about color. He first started work towards the system in 1898 and published it 100 % form within a Color Notation in 1905.
The very first embodiment of your system (the 1905 Atlas) had some deficiencies as a physical representation of the theoretical system. These were improved significantly from the 1929 Munsell Book of Color and through a thorough series of experiments performed by the Optical Society of America inside the 1940s leading to the notations (sample definitions) for that modern Munsell Book of Color. Though several replacements for that 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 product is still popular, by, and the like, ANSI to define hair and skin colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during selecting shades for dental restorations, and breweries for matching beer colors.