Color standard of color matching

By scaling the three attributes of color-hue, lightness and saturation, we can measure color by numbers. 1905, American painter A.H. Munsell invented a model of a type of sphere, which showed all three parameters representing colors, and each part in the three-dimensional model represented a specific color. As a method of surface color classification and calibration, Munsell color system has been widely used in the world, and its representation method is HV/C, where H stands for hue and V stands for numerical value. CIE has developed other digital color methods, two of which are the YXY color space method and the L*a*b* color space method. The former was invented at 193 1 according to the tristimulus value XYZ specified by CIE, and the latter was invented at 1976, in order to give a more uniform color difference with respect to parallax. These three color systems have a certain conversion relationship.

Munsell coordinate system is still the standard of paint film color in coating industry. Gb/t 3181-1995 color standard includes the colors of main paint products that are often produced and used, and consists of 83 colors. See GSB G5 100-94 for paint film color standard card (color card). The full name of a color code is expressed by a number plus a name, and the number consists of one or two uppercase English letters and two Arabic numerals. Use English letters to represent hue (see Table 4- 1 1), and use Arabic numerals to distinguish different colors of the same hue. The names of color standards adopt customary names, such as red, dark yellow, medium green and light gray. Table 4- 12 lists the numbers and names of various color standards of commonly used coatings, the color labels corresponding to GB/T 6749-97 and the serial numbers of GSB G5 100 1.

Color paint films are divided into ten categories according to their main colors, plus eleven categories of achromatic colors, as shown in Table 4- 1 1. Color paint film is HV/C; No color: NV. Table 4- 1 1 Classification and symbol color of hue red yellow red yellow green blue purple achromatic color symbol R YR Y GY G BGB PB P RP N Munsell system three attributes indicate the meaning of symbol: the hue symbol is H, indicating that the object is one of the three attributes of red, yellow, green, blue and purple or an intermediate color, and the arrangement of hue is shown in Figure 4-3, which is represented by numbers and letters. The symbol of lightness is V, which represents one of the three color attributes of how much light an object reflects. The perceptual differences of lightness between rational black is 0, white is 10 and 0 ~ 10 are divided by equivalence. The symbol of saturation and chroma is c, which indicates the degree to which the color deviates from the gray with the same brightness. Chromaticity can be divided into 0 ~ 20, and achromatic color is generally below 0.5. Table 4- 12 Color names, Munsell numbers and color numbers of corresponding national standards of commonly used coatings; Munsell color number HV/C (hue lightness/chroma) corresponds to GB/T 3 18 1 corresponds to GSB color number G5 100 1.

black

white

brown

Marine ash

lead

Light blue

iron oxide red

Elephant's tusks

pearl

lovely

tangerine

purplish red