In colorimetry, the Munsell color method is one space that specifies colors depending on three color dimensions: hue, value (lightness), and chroma (color purity). It was actually developed by Professor Albert H. Munsell from the first decade of the 20th century and adopted with the USDA as being the official color system for soil research from 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 to separate hue, value, and chroma into perceptually uniform and independent dimensions, and that he was the first to systematically illustrate the colours 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 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perception, Munsell’s system has outlasted its contemporary color models, despite the fact that it really has been superseded for some uses by models including CIELAB (L*a*b*) and CIECAM02, it is still in wide use today.
Munsell’s color sphere, 1900. Later, munsell soil color chart found out that if hue, value, and chroma were to be kept perceptually uniform, achievable surface colors could not forced into a regular shape.
Three-dimensional representation in the 1943 Munsell renotations. Notice the irregularity of the shape in comparison with Munsell’s earlier color sphere, at left.
The program consists of three independent dimensions which is often 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, helping to make the resulting shape quite irregular. As Munsell explains:
Desire to fit a chosen contour, including the pyramid, cone, cylinder or cube, in addition to not enough 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 into five principal hues: Red, Yellow, Green, Blue, and Purple, along with 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. All these 10 steps, with all the named hue given number 5, will be broken into 10 sub-steps, in order that 100 hues are provided integer values. In reality, color charts conventionally specify 40 hues, in increments of 2.5, progressing as for example 10R to 2.5YR.
Two colors of equal value and chroma, on opposite sides of any hue circle, are complementary colors, and mix additively for 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 over the color solid, from black (value ) at the bottom, to white (value 10) on the top.Neutral grays lie over the vertical axis between monochrome.
Several color solids before Munsell’s plotted luminosity from black at the base to white on top, having a gray gradient between the two, 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) along the equator.
Chroma, measured radially from the core of each slice, represents the “purity” of your color (relevant to saturation), with lower chroma being less pure (more washed out, as with pastels). Keep in mind that there is not any intrinsic upper limit to chroma. Different parts of the colour space have different maximal chroma coordinates. As an illustration light yellow colors have considerably more potential chroma than light purples, due to nature in the eye and also the physics of color stimuli. This resulted in a variety of possible chroma levels-around our prime 30s for some hue-value combinations (though it is sometimes complicated or impossible to help make physical objects in colors of such high chromas, and so they cannot be reproduced on current computer displays). Vivid solid colors happen to be in the plethora of approximately 8.
Keep in mind that the Munsell Book of Color contains more color samples than this chart for both 5PB and 5Y (particularly bright yellows, as much as 5Y 8.5/14). However, they are certainly not reproducible in the sRGB color space, that has a limited color gamut designed to match that of televisions and computer displays. Note additionally that there 85dexupky no samples for values (pure black) and 10 (pure white), which can be theoretical limits not reachable in pigment, and no printed samples of value 1..
A color is fully specified by listing the 3 numbers for hue, value, and chroma in that order. For instance, a purple of medium lightness and fairly saturated will be 5P 5/10 with 5P meaning the hue during the purple hue band, 5/ meaning medium value (lightness), as well as a chroma of 10 (see swatch).
The concept of employing a three-dimensional color solid to represent all colors was made through 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, an individual 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 more sophisticated, with Kirschmann’s even recognizing the real difference in value between bright colors of different hues. But every one of them 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 connection between hue, value, and chroma had not been understood.
Albert Munsell, an artist and professor of art in the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to create a “rational strategy to describe color” that will use decimal notation rather than color names (which he felt were “foolish” and “misleading”), that he can use to instruct his students about color. He first started work towards the program in 1898 and published it 100 % form inside a Color Notation in 1905.
The initial embodiment in the 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 an extensive group of experiments carried out by the Optical Society of America inside the 1940s resulting in the notations (sample definitions) to the modern Munsell Book of Color. Though several replacements to the Munsell system happen to be invented, building on Munsell’s foundational ideas-for example 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 widely 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.