《太平广记·卷二百二十四·相四》
只要你仔细地看他，十天以后可以隐约地辨别出白色；半年以后，就能看清楚五种颜色了。老僧教导黄彻说：如果能在黑暗中辨别清楚五色彩丝，回去就可以在白天为人相面，预测未来了。
即洞然而得矣。命之曰：以若暗中之视五采，回之白昼占人。
As long as you look at it carefully, you can vaguely distinguish white after ten days; after half a year, you will be able to see the five colors clearly. The old monk taught Huang Che, saying: If you can distinguish the five colors of silk in the dark, you can go back and look at people's faces and predict the future in the daytime.