Spectrophotometric and calculative determination methods of textile color-difference threshold considering the observing condition

Purpose This study aims to investigate the varying color-difference thresholds for textiles under various illuminants. Design/methodology/approach To determine color-difference thresholds, 108 fabric samples with widely ranging colors were spectrophotometrically measured and visually assessed under four illumination conditions (correlated color temperatures of 2,856 K and 6,504 K; illuminances of 100 lx and 2,000 lx). Findings The mean spectrophotometric color-difference threshold (solely based on the textile’s physical color attributes in machine vision) was 4.22 ΔE*ab; thus, a mechanically measured color difference between two textiles (regardless of illuminant) of less than 4.22 ΔE*ab indicated individuals’ inability to differentiate between two textiles. The calculated color-difference thresholds, which reflected the color differences perceived by people considering textiles’ physical color attributes and the environmental factors in which they were observed, were higher than the spectrophotometric thresholds. This meant that under various illuminants, people had greater difficulty perceiving color differences than mechanically measured spectrophotometric thresholds. Particularly, larger discrepancies between the two threshold types occurred under reddish illuminants of 2,856 K than under bluish-white illuminants of 6,504 K. Furthermore, the extent to which people perceived color differences as distinct from actual differences under illumination was larger for greenish-blue textiles than for textiles of other hues. Originality/value The determined spectrophotometric and calculative color-difference thresholds for textiles can help fashion companies predict consumers’ perceptions of the colors of their textile products under various illuminants and, accordingly, appropriately plan colors of products and create standards for color quality control.