《黄帝内经·素问·举痛论》
岐伯说：五脏六腑在面部各有所属部位，望面部五色的变化就可以诊断疾病，如黄色赤色主热，白色主寒，青色黑色主痛，这都是通过望诊可以了解的。
岐伯曰：五脏六腑，固尽有部，视其五色，黄赤为热，白为寒，青黑为痛，此所谓视而可见者也。
Qi Bo said: The five viscera and six bowels each have their own corresponding areas on the face. Looking at the changes in the five colors of the face can diagnose diseases, such as yellow and red indicating heat, white indicating cold, green and black indicating pain, which can all be understood by looking.