In colorimetry, the Munsell color method is a color space that specifies colors depending on three color dimensions: hue, value (lightness), and chroma (color purity). It had been developed by Professor Albert H. Munsell within the first decade in the twentieth century and adopted by the USDA since the official color system for soil research within the 1930s.
Several earlier color order systems had placed colors in a three-dimensional color solid of merely one form or other, but Munsell was the first to separate hue, value, and chroma into perceptually uniform and independent dimensions, and he was the first one 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 on a firm experimental scientific basis. Because of this basis in human visual perception, Munsell’s system has outlasted its contemporary color models, even though it really has been superseded for some uses by models such as CIELAB (L*a*b*) and CIECAM02, it is still in wide use today.
Munsell’s color sphere, 1900. Later, munsell color chart found out that if hue, value, and chroma would be kept perceptually uniform, achievable surface colors could not be forced in a regular shape.
Three-dimensional representation of the 1943 Munsell renotations. See the irregularity of your shape in comparison to Munsell’s earlier color sphere, at left.
The machine consists of three independent dimensions which can be represented cylindrically in three dimensions as being 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 close to perceptually uniform because he may make them, that makes the resulting shape quite irregular. As Munsell explains:
Want to fit a chosen contour, including the pyramid, cone, cylinder or cube, in conjunction with an absence of proper tests, has generated many distorted statements of color relations, and it also 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 separated into five principal hues: Red, Yellow, Green, Blue, and Purple, together with 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. Each of these 10 steps, together with the named hue given number 5, will then be broken into 10 sub-steps, so that 100 hues are shown 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 any hue circle, are complementary colors, and mix additively towards 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 across the color solid, from black (value ) at the end, to white (value 10) towards the top.Neutral grays lie over the vertical axis between black and white.
Several color solids before Munsell’s plotted luminosity from black on the bottom to white on top, by using 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) along the equator.
Chroma, measured radially from the centre of each slice, represents the “purity” of a color (linked to saturation), with lower chroma being less pure (more washed out, like pastels). Be aware that there is absolutely no intrinsic upper limit to chroma. Different regions 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 nature of the eye and also the physics of color stimuli. This triggered an array of possible chroma levels-around the high 30s for many hue-value combinations (though it is not easy or impossible to help make physical objects in colors of the high chromas, and they cannot be reproduced on current computer displays). Vivid solid colors happen to be in the range of approximately 8.
Keep in mind 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 within the sRGB color space, that features a limited color gamut created to match those of 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, and no printed examples of value 1..
One is fully specified by listing the three numbers for hue, value, and chroma in this order. As an illustration, 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), plus a chroma of 10 (see swatch).
The notion of utilizing a three-dimensional color solid to represent all colors was developed through the 18th and 19th centuries. A number of shapes for this kind of 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, and a slanted double cone by August Kirschmann in 1895. These systems became progressively modern-day, with Kirschmann’s even recognizing the 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, your relationship between hue, value, and chroma was not understood.
Albert Munsell, an artist and professor of art at the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to create a “rational strategy to describe color” that could use decimal notation instead of color names (that he felt were “foolish” and “misleading”), that he can use to instruct his students about color. He first started work towards the machine in 1898 and published it entirely form in A Color Notation in 1905.
The initial embodiment of your system (the 1905 Atlas) had some deficiencies like a physical representation from the theoretical system. These were improved significantly from the 1929 Munsell Book of Color and thru a comprehensive combination of experiments completed by the Optical Society of America within the 1940s leading to the notations (sample definitions) for your modern Munsell Book of Color. Though several replacements to the Munsell system have been invented, building on Munsell’s foundational ideas-including 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, and others, ANSI to define skin and hair colors for forensic pathology, the USGS for matching soil colors, in prosthodontics during picking shades for dental restorations, and breweries for matching beer colors.