... Rz,Rx,Rz and yellowness index IntroductionZB-A colour tester is the professional instrument to ... chromaticity coordinate x10, y10, z10;lightness L*;chrominance a*, b*;chromaticity C*ab;hue angle h*ab; ... ΔC*ab, hue difference ΔH*ab, Hunter system L, a,b.2.Measure ISO(R457)and Rz3. Measure ... Adopted CIE 1964 supplementary standard colorimetric system and CIE 1976 (L*a*b) color space and color difference ...