（素问经络论 全）
黄帝问曰∶夫络脉之见也，其五色各异，青黄赤白黑不同，其故何也？岐伯对曰∶经有常色而络无常变也。（经有五
行之分，故有常色。络兼阴阳之应，故无常变。）帝曰∶经之常色何如？岐伯曰∶心赤肺白肝青脾黄肾黑，皆亦应其经脉
之色也。（五脏合于五行，故五色各有所主，而经脉之色亦与本脏相应，是为经之常色。按此节但言五脏而不及六腑者，
大都经文皆以五脏为主，言五脏则六腑在其中矣。凡三阴三阳十二经之常色，皆当以此类推。）帝曰∶络之阴阳，亦应其
经乎？岐伯曰∶阴络之色应其经，阳络之色变无常，随四时而行也。（此言络有阴阳而色与经应亦有同异也。脉度篇曰∶
经脉为里，支而横者为络，络之别者为孙。故合经络而言，则经在里为阴，络在外为阳；若单以络脉为言，则又有大络
孙络在内在外之别。深而在内者是为阴络，阴络近经，色则应之，故分五行以配五脏而色有常也。浅而在外者，是为阳
络，阳络浮显。色不应经，故随四时之气以为进退，而变无常也。观百病始生篇曰∶阳络伤则血外溢，阴络伤则血内溢。
其义可知。何近代诸家之注，皆以六阴为阴络，六阳为阳络，岂阳经之络必无常，阴经之络必无变乎？皆误也。）寒多则
凝泣，凝泣则青黑；热多则淖泽，淖泽则黄赤。此即言阳络之变色也。泣，涩同。淖音闹，濡润也。）此皆常色，谓之无
病。五色具见者，谓之寒热。（如前五色之应五脏者，皆常色也。常色者，无病之色也。若五色具见，则阴阳变乱，失其
常矣，故为往来寒热之病。）帝曰∶善。
*Suwen: Lun Jing Luo* (Complete Text)
The Yellow Emperor asked, "When the collateral vessels (Luo Mai) are visible, their colors vary among green, yellow, red, white, and black. What is the reason for this?"
Qibo replied, "The primary meridians (Jing Mai) have constant colors, whereas the collateral vessels do not have fixed changes." (The primary meridians are divided according to the Five Elements, hence they have constant colors. The collateral vessels respond to both Yin and Yang, hence their colors change without a fixed pattern.)
The Yellow Emperor asked, "What are the constant colors of the primary meridians?"
Qibo said, "The Heart corresponds to red, the Lungs to white, the Liver to green, the Spleen to yellow, and the Kidneys to black. These all correspond to the colors of their respective primary meridians." (The Zang organs harmonize with the Five Elements, so each of the five colors has its specific dominion, and the color of the primary meridians also corresponds to their respective Zang organs; this constitutes the constant color of the meridians. Note that this section mentions only the Zang organs and not the Fu organs, because the classic text generally takes the Zang organs as the main focus; by discussing the Zang organs, the principles of the Fu organs are included therein. The constant colors of all Twelve Primary Meridians—Three Yin and Three Yang—should be inferred in this manner.)
The Yellow Emperor asked, "Do the Yin and Yang of the collateral vessels also correspond to their respective meridians?"
Qibo said, "The color of the Yin collaterals corresponds to the meridian, but the color of the Yang collaterals varies without constancy, following the changes of the four seasons." (This statement indicates that while collaterals are divided into Yin and Yang, their correspondence to meridian colors has both similarities and differences. The *Lingshu: Mai Du* chapter states: 'Primary meridians are deep within, while branches that run horizontally are collateral vessels; further subdivisions of collaterals are Sun collaterals.' Thus, speaking of meridians and collaterals together, the meridians are internal and thus Yin, while the collaterals are external and thus Yang. However, speaking solely of collateral vessels, there is a distinction between large collaterals and Sun collaterals located internally or externally. Those that are deep and internal are called Yin collaterals. Since Yin collaterals are close to the primary meridians, their colors correspond to them; therefore, they are divided into Five Elements to match the Zang organs, resulting in constant colors. Those that are shallow and external are called Yang collaterals. Since Yang collaterals are superficial and prominent, their colors do not correspond to the primary meridians; instead, they advance and retreat according to the Qi of the four seasons, changing without constancy. Observing the *Suwen: Bai Bing Shi Sheng* chapter, which states: 'If Yang collaterals are injured, blood overflows externally; if Yin collaterals are injured, blood overflows internally,' the meaning becomes clear. Why do modern commentators define the six Yin meridians as Yin collaterals and the six Yang meridians as Yang collaterals? Do the collaterals of Yang meridians necessarily lack constancy, while those of Yin meridians necessarily lack variation? This is erroneous.)
"When cold predominates, the Qi and Blood coagulate and become stagnant; stagnation results in green or black colors. When heat predominates, the Qi and Blood become moist and slippery; slipperiness results in yellow or red colors. This describes the color changes of Yang collaterals. ('Qi' here is interchangeable with 'Se', meaning stagnant/astringent. 'Nao' is pronounced 'nao', meaning moist and lubricated.) These are considered normal colors, indicating the absence of disease. If all five colors appear simultaneously, it is termed a condition of alternating cold and heat." (As mentioned previously, the correspondence of the five colors to the Zang organs represents normal colors. Normal colors indicate a state of health. If all five colors appear, it signifies chaos in Yin and Yang, loss of normalcy, and thus indicates a disease of alternating cold and heat.)
The Yellow Emperor said, "Excellent."