Detail of GB/T 21898-2023

Introduction of GB/T 21898-2023

Method of specification for textile colors 1 Scope This document specifies the color solid, notation, measurement and color difference assessment of textile colors. This document is applicable to the specification for textile colors, and may be used as reference for color specification in other industries related to textiles. 2 Normative references The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3977 Specification of colors GB/T 3978 Standard illuminants and geometric conditions GB/T 3979 Methods for the measurement of object color GB/T 5698 Glossary of color terms GB/T 6529 Textiles - Standard atmospheres for conditioning and testing GB/T 7771 Measurement of special metamerism index - Change in illuminant GB/T 8424.3 Textiles - Tests for colour fastness - Calculation of colour differences GB/T 9340 Methods for color measurement of fluorescent specimens GB/T 15610 Method for visual appraisal of metamerism ISO 23603 Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour CIE 015 Colorimetry 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 5698 and the following apply. 3.1 hue H one of the three visual attributes of colors, which indicates the characteristics of red, yellow, green, blue, purple, etc. 3.2 value V one of the three visual attributes of colors, which indicates the brightness of color on the surface of an object, and divided between ideal black and ideal white 3.3 chroma C one of the three visual attributes of colors, which indicates the grayness of color on the surface of an object, and is represented by the difference from the achromatic color with equal value [Source: GB/T 5698-2001, 5.9, modified] 3.4 special metamerism index M [CIE] color difference caused by changing the reference illuminant into other illuminants or simulated light sources, or changing the reference observer into other observers when the metameric color stimuli are isochromatic under the reference illuminant, observer and geometric conditions Note: When analyzing the color metamerism of objects, the reference illuminant D65 is changed to other test illuminant t, and the special metamerism index is represented by Mt,ilm; when analyzing the spectral quality of simulated light source, the special metamerism index of visible light part is represented by Mv, and that of ultraviolet part is represented by Mu; when analyzing the observer changes, the special metamerism index is represented by Mobs. [Source: CIE 015:2018, 9.1, modified] 4 Color solid 4.1 Composition The cylindrical coordinate system of color consists of achromatic system and chromatic system, with the middle vertical axis from bottom to top and from black to white as the value axis, the distance perpendicular to the middle vertical axis as the chroma, and the top angle around the middle vertical axis as the hue angle. The color solid is composed of three attributes: hue, value and chroma.

Contents of GB/T 21898-2023

Contents 1 Scope 2 Normative references 3 Terms and definitions 4 Color solid 5 Notations 6 Measurement and color difference assessment Annex A (Normative) Relationship between value notation V and luminance factor Y10 Annex B (Normative) Color data values corresponding to partial notations of textile colors