The color depth, an important attribute of color, can reflect the amount of dye partly, which has important functions on the evaluation of color-fastness and strength of dyes, dyeing effect of fabric, computer color matching, and so on. Natural Color System, an internationally accepted color system, orders colors by three parameters (blackness, chromaticness, and hue). The color depth has not been specified within the Natural Color System. This article tries to find the regularity of the sample with equal-depth in Natural Color System. Firstly, 1950 color samples in Natural Color System were measured using an X-Rite Color i7 Spectrophotometer, and their color depths were calculated by five color depth formulas. Then, trend analysis and mathematical modeling methods were used to achieve the connection between the color depth and the notations of Natural Color System basing on color depth theories. Results show that, in Natural Color System, the color samples with the same distance to pure white do not have equal depth; but the color samples with the same nuance (equal blackness, whiteness and chromaticness) have broadly equal color depth, and their average coefficient values are lower than that of Society of Dyers and Colourists Standard Depths. Besides, regressive formulas were built, with which the color depths of any chips in Natural Color System can be calculated broadly by their notation.

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自然色系中等深色样的研究

色深是颜色的一个重要属性，能部分反映染料的用量，对评价染料的色牢度和强度、织物的染色效果、计算机配色等具有重要作用。Natural Color System 是一种国际通用的颜色系统，它通过三个参数（黑度、色度和色调）对颜色进行排序。颜色深度尚未在 Natural Color System 中指定。本文试图在自然色系中寻找等深样本的规律性。首先使用X-Rite Color i7分光光度计测量Natural Color System中的1950个颜色样本，并通过五个色深公式计算它们的色深。然后，基于色深理论，采用趋势分析和数学建模方法，实现色深与自然色系符号的联系。结果表明，在自然色系中，与纯白色距离相同的颜色样本的深度不相等；但具有相同细微差别（相同的黑度、白度和色度）的颜色样本具有大致相同的色深，并且它们的平均系数值低于Society of Dyers and Colourists Standard Depths。此外，还建立了回归公式，通过该公式可以大致计算自然色系统中任何芯片的颜色深度。与纯白色距离相同的色样，深度不同；但具有相同细微差别（相同的黑度、白度和色度）的颜色样本具有大致相同的色深，并且它们的平均系数值低于Society of Dyers and Colourists Standard Depths。此外，还建立了回归公式，通过该公式可以大致计算自然色系统中任何芯片的颜色深度。与纯白色距离相同的色样，深度不同；但具有相同细微差别（相同的黑度、白度和色度）的颜色样本具有大致相同的色深，并且它们的平均系数值低于Society of Dyers and Colourists Standard Depths。此外，还建立了回归公式，通过该公式可以大致计算自然色系统中任何芯片的颜色深度。