纺织品样品（暴露在光线下颜色发生变化，但在黑暗中储存时几乎恢复其原始色调的彩色纺织品）暴露在高强度光线下的时间比引起永久性变化所需的时间短得多。暴露后立即使用灰阶评估试样颜色的变化。然后将样本储存在黑暗中，并再次评估。

A specimen of the textile (coloured textiles which change in colour on exposure to light but which virtually return to their original shade when stored in the dark) is exposed to light of high intensity for a time much shorter than that necessary to cause a permanent change. The change in colour of the specimen is assessed immediately after exposure, using the grey scale. The specimen is then stored in the dark and assessed again.