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 had been produced by Professor Albert H. Munsell within the first decade in the twentieth century and adopted from the USDA as being the official color system for soil research inside the 1930s.
Several earlier color order systems had placed colors in to a three-dimensional color solid of a single form or another, but Munsell was the first to separate hue, value, and chroma into perceptually uniform and independent dimensions, and he was the first to systematically illustrate the colors in three-dimensional space. Munsell’s system, particularly the later renotations, is founded 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in human visual perception, Munsell’s system has outlasted its contemporary color models, even though this has been superseded for a few uses by models such as CIELAB (L*a*b*) and CIECAM02, it can be still in wide use today.
Munsell’s color sphere, 1900. Later, munsell soil color chart learned that if hue, value, and chroma were to be kept perceptually uniform, achievable surface colors could not really forced in a regular shape.
Three-dimensional representation in the 1943 Munsell renotations. See the irregularity of your shape when compared with Munsell’s earlier color sphere, at left.
The system consists of three independent dimensions which may be represented cylindrically in three dimensions for an irregular color solid: hue, measured by degrees around horizontal circles; chroma, measured radially outward from your neutral (gray) vertical axis; and value, measured vertically from (black) to 10 (white). Munsell determined the spacing of colors along these dimensions through taking measurements of human visual responses. In each dimension, Munsell colors are as close to perceptually uniform because he can make them, making the resulting shape quite irregular. As Munsell explains:
Want to fit a chosen contour, for example the pyramid, cone, cylinder or cube, in addition to not enough proper tests, has resulted in 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 divided into five principal hues: Red, Yellow, Green, Blue, and Purple, as well as 5 intermediate hues (e.g., YR) halfway between adjacent principal hues. Each one of these 10 steps, with all the named hue given number 5, is then broken into 10 sub-steps, so that 100 hues are provided 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 on 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 along the color solid, from black (value ) at the end, to white (value 10) at the very 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 at the top, using a gray gradient between the two, nevertheless these systems neglected to keep 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 middle of each slice, represents the “purity” of your color (associated with saturation), with lower chroma being less pure (more washed out, as in pastels). Be aware that there is not any intrinsic upper limit to chroma. Different parts of the hue space have different maximal chroma coordinates. As an example light yellow colors have considerably more potential chroma than light purples, as a result of nature in the eye as well as the physics of color stimuli. This generated a wide array of possible chroma levels-up to the high 30s for several hue-value combinations (though it is not easy or impossible to make physical objects in colors of the high chromas, and so 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 for 5PB and 5Y (particularly bright yellows, around 5Y 8.5/14). However, they are certainly not reproducible within the sRGB color space, that has a limited color gamut made to match that of televisions and computer displays. Note as well 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 the 3 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 the hue in the midst of the purple hue band, 5/ meaning medium value (lightness), plus a chroma of 10 (see swatch).
The notion of by using a three-dimensional color solid to represent all colors was developed through the 18th and 19th centuries. Many different shapes for this type 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 based upon 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 at the Massachusetts Normal Art School (now Massachusetts College of Art and Design, or MassArt), wanted to generate a “rational strategy to describe color” that will use decimal notation as an alternative to color names (that he felt were “foolish” and “misleading”), which he can use to train his students about color. He first started work with the machine in 1898 and published it in full form in the Color Notation in 1905.
The very first embodiment of your system (the 1905 Atlas) had some deficiencies like a physical representation of your theoretical system. They were improved significantly from the 1929 Munsell Book of Color and thru a substantial series of experiments performed by the Optical Society of America in the 1940s contributing to the notations (sample definitions) for the modern Munsell Book of Color. Though several replacements for that Munsell system happen to be invented, building on Munsell’s foundational ideas-like 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 popular, by, and the like, 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.