... for paper and pulps GB/T 12911: Paper and board-Determination of ink absorbencyHG/T 3862: Plastics-Yellow index test methodGB 9087 ... stimulus value X10, Y10, Z10, chromaticity coordinate X10, Y10, lightness L*, chrominance a*, b*,chromaticity C*ab, hue angle h*ab ... d, excited purity Pe, color difference E*ab, lightness difference L*, chromaticity difference C*ab, hue difference H*ab, Hunter system ...