The foundation of a color-chip evaluation system of jadeite-jade green with color difference control of medical device

摘要

Based on the uniform color space International Commission on Illumination (CIE) 1976 L*a*b*, the color green of 728 pieces of jadeite-jade was quantitatively characterized by the spectrophotometer Color i5. The color-chip system of jadeite-jade green with color difference control was then researched. First, with the help of the basic color difference formula, the concentrated plot areas of L*a(35, 55), a*a(-30, -45), and b*a(0, 35) of jadeite-jade color green were taken as the color center, which was in accordance with the CIE standard green (L* = 56, a* = -32, b* = 0) and high chroma green (L* = 56, a* = -45, b* = 0). Second, the total plot areas of h0a(125.21A degrees, 171.10A degrees) and L*a(5, 95) of jadeite-jade color green were considered as color gamut, which was in accordance with the scope from CIE standard yellowish green to bluish green. In consideration of the color green plot areas of jadeite-jade and China National Standard GB/T 23885-2009 "Jadeite-Jade Grading", Delta L* = 5, Delta a* = 10, and Delta b* = 10 were calculated to form a color-chip system of jadeite-jade color green with Delta E* = 15 from one chip to another, and 521 chips were then achieved. Color chips were reduced or added for sparse or intense plot points. As a result, the color-chip system was condensed into 126 chips based on lightness and then merged into 19 areas with Delta L* = 5. With cluster analysis, 126 chips were graded into nine levels. The commercial evaluation of jadeite-jade color green showed that these levels were sequenced from the top quality fancy vivid green to the last faint green. One-way ANOVA verified the reasonability of the nine levels. Fisher discriminant analysis demonstrated that very high accuracy of 99.21 % was achieved, and only one group from 126 groups was misjudged. Thus, based on the statistical analysis of color parameters in the uniform color space, the color-chip evaluation system of jadeite-jade green with color difference control could be used with high accuracy.