Color Inconstancy of Chromatic and Achromatic Textile Fabrics with Changes in the Correlated Color Temperature and Luminance of the Light Source

Abstract

This study quantitatively analyzed how the color appearance of textile fabrics of varying lightness, chroma, and hue changes under a broad spectrum of illumination conditions. The color appearances of 203 chromatic (R, YR, Y, GY, G, BG, B, and RB) and achromatic fabrics were measured spectroradiometrically under 16 light sources with different correlated color temperatures (2700, 4000, 5000, and 6500 K) and luminances (50, 100, 500, and 1000 cd/m²). The color appearance values were compared with the spectrophotometrically measured physical color values of the fabrics, which were regarded as their true colors. The differences ranged up to 12.45 ∣ΔL^*₁₀∣, 19.32 ∣ΔC^*_ab,10∣, 161.83∣Δh_{ab, 10}∣, and 16.70 ΔE_CMC(2:1) units, which were significantly higher than the color discrimination thresholds of the human eye. Among 9 hue groups of fabrics, the color appearances of BG (bluish-green) fabrics were generally most affected by light sources, while those of achromatic fabrics were least affected with mean ΔE_CMC(2:1) of 6.32 and 1.03, respectively. It was also found that the correlated color temperature of light sources significantly affected all the lightness, colorfulness, and hue of fabrics, and the different trends of these effects were observed for different hue groups. Unlike current knowledge, light sources with a correlated color temperature of 6500 K did not always produce color appearances that most closely resemble the actual physical colors. Meanwhile, the luminance of light sources did not have a profound effect on the color appearances of fabrics.