明堂察色。以脏腑部位为体。以气色诊法为用。故分观之。可以识其常。合参之。可以通其变。然究其常变。
而原其始终。要不离乎阴阳之旨。盖阴阳者。天地之道也。万物之纲纪。变化之父母。生杀之本始。神明之
府也。故以五色分言之。青属少阳。旺于春。赤属太阳。旺于夏。白属少阴。旺于秋。黑属太阴。旺于冬。黄属中
央土。寄于四季。旺于长夏。以六部分言之。外者上者左者皆为阳。内者下者右者皆为阴。以十法分言之。
浮清甚散泽为阳。沉浊微抟夭为阴。于是乎气色兼见。部位互考。则阴阳相错。阴中有阳。阳中有阴。此阴
阳之总纲也。顾阴阳之道。阳清阴浊。阳升阴降。阳热阴寒。阳动阴静。阳外阴内。阳上阴下。阳左阴右。阳道
实。阴道虚。阳常有余。阴常不足。是以色见诸阳者易治。见诸阴者难疗。外感阴病见阳色者易治。阳病见
阴色者难疗。内伤阳病见阴色者易治。阴病见阳色者难疗。凡此阴阳之理。既可合气色部位以相参。亦
可合脏腑病症以相证者也。易传曰。一阴一阳之谓道。阴阳不测之谓神。内经曰。得神者昌。失神者亡。阴
阳变化。一以贯之矣。
尝考内经望法。以为五色形于外。五脏应于内。犹根本之与枝叶也。色脉形肉。不得相失也。故有病必有
色。内外相袭。如影随形。如鼓应桴。远者。司外揣内。近者。司内揣外。五色之见。莫不相输应焉。何言之。肝属
东方木。通于风气。在时为春。在窍为目。在志为怒。在变动为语。其藏魂。其脉弦。其声呼。其音角。其臭臊。其
味酸。其液泣。其合筋。其荣爪。其腑胆。其日甲乙。其时寅卯。其经足厥阴。此青色之应也。心属南方火。通于
暑气。在时为夏。在窍为舌。在志为喜。在变动为噫。其藏神。其主血。其声笑。其音征。其臭焦。其味苦。其液汗。
其合脉。其荣色。其腑小肠。其日丙丁。其时巳午。其经手少阴。其包络手心主。此赤色之应也。脾属中央土。
通于湿气。在时为长夏。在窍为口。在志为思。在变动为吞。其藏意。其脉缓。其声歌。其音宫。其臭香。其味甘。
其液涎。其合肉。其荣唇。其腑胃。其日戊己。其时辰戌丑未。其经足太阴。此黄色之应也。肺属西方金。通于
燥气。在时为秋。在窍为鼻。在志为悲。在变动为咳。其藏魄。其主气。其脉毛。其声哭。其音商。其臭腥。其味辛。
其液涕。其合皮。其荣毛。其腑大肠。其日庚辛。其时申酉。其经手太阴。此白色之应也。肾属北方水。通于寒
气。在时为冬。在窍为耳。在志为恐。在变动为欠。其藏志。其脉石。其声呻。其音羽。其臭腐。其味咸。其液唾。其
合骨。其荣发。其腑三焦膀胱。其日壬癸。其时亥子。其经足少阴。此黑色之应也。色之应乎脏者。亦应其腑。
应乎腑者。亦应其经。但当分其部位之内外。察其气色之阴阳。五色之见。莫不相输应焉。顾应者。常也。不
应者。变也。知其常变。则知其生克矣。知其生克。则知其逆从矣。五脏各有病证声色臭味。当与气口明堂
相应焉。其太过不及。相生相克者。皆病也。从外知内。盖本乎此。
观察明堂（鼻部）的气色，以脏腑在面部的对应部位为根本，以气色诊法为应用。因此，分别观察各个部位，可以了解其正常状态；综合参详，可以通晓其变化规律。然而，探究其正常与变化的本质，并追溯其始终原因，总离不开阴阳的宗旨。
所谓阴阳，是天地运行的规律，万物的纲纪，变化的根源，生杀的本始，神明产生的府库。因此，从五色分别来说：青色属于少阳，旺盛于春季；赤色属于太阳，旺盛于夏季；白色属于少阴，旺盛于秋季；黑色属于太阴，旺盛于冬季；黄色属于中央土，寄寓于四季之中，旺盛于长夏。
从六部分别来说：外部、上部、左侧都属于阳；内部、下部、右侧都属于阴。从“十法”分别来说：浮、清、甚、散、泽属于阳；沉、浊、微、抟、夭属于阴。于是气色同时显现，部位相互参照，则阴阳交错，阴中有阳，阳中有阴。这是阴阳的总纲。
至于阴阳的道理：阳清阴浊，阳升阴降，阳热阴寒，阳动阴静，阳外阴内，阳上阴下，阳左阴右，阳道实，阴道虚，阳常有余，阴常不足。因此，面色见于阳证者容易治疗，见于阴证者难以治愈。外感病中，阴病见到阳色者容易治疗，阳病见到阴色者难以治愈；内伤病中，阳病见到阴色者容易治疗，阴病见到阳色者难以治愈。
所有这些阴阳的道理，既可以结合气色和部位来相互参照，也可以结合脏腑和病症来相互印证。《易经·系辞》说：“一阴一阳交替变化叫做道，阴阳变化莫测叫做神。”《黄帝内经》说：“得到神机昌隆，失去神机灭亡。”阴阳的变化，可以用这一原则贯穿始终。
我曾考察《黄帝内经》中的望诊方法，认为五色表现于外，五脏应于内，就像根本与枝叶的关系一样。色、脉、形、肉，不能相互背离。所以有病必然有色，内外相互影响，如同影子跟随形体，如同鼓声应和击鼓。远观可以通过外在表现推测内在病变，近察可以通过内在病变推断外在表现。五色的显现，没有不相呼应的。为什么这样说？
肝属东方木，通于风气，在季节为春，在孔窍为目，在情志为怒，在变动为言语异常，其藏魂，其脉象弦，其声音为呼，其音律为角，其气味为臊，其味道为酸，其体液为泪，其合筋，其荣华在爪甲，其腑为胆，其日为甲乙，其时为寅卯，其经脉为足厥阴经。这是青色的对应关系。
心属南方火，通于暑气，在季节为夏，在孔窍为舌，在情志为喜，在变动为嗳气，其藏神，其主血，其声音为笑，其音律为徵，其气味为焦，其味道为苦，其体液为汗，其合脉，其荣华在面色，其腑为小肠，其日为丙丁，其时为巳午，其经脉为手少阴经，其包络为手心主经。这是赤色的对应关系。
脾属中央土，通于湿气，在季节为长夏，在孔窍为口，在情志为思，在变动为吞咽，其藏意，其脉象缓，其声音为歌，其音律为宫，其气味为香，其味道为甘，其体液为涎，其合肉，其荣华在唇，其腑为胃，其日为戊己，其时辰为辰戌丑未，其经脉为足太阴经。这是黄色的对应关系。
肺属西方金，通于燥气，在季节为秋，在孔窍为鼻，在情志为悲，在变动为咳嗽，其藏魄，其主气，其脉象毛，其声音为哭，其音律为商，其气味为腥，其味道为辛，其体液为涕，其合皮，其荣华在毫毛，其腑为大肠，其日为庚辛，其时为申酉，其经脉为手太阴经。这是白色的对应关系。
肾属北方水，通于寒气，在季节为冬，在孔窍为耳，在情志为恐，在变动为呵欠，其藏志，其脉象石，其声音为呻，其音律为羽，其气味为腐，其味道为咸，其体液为唾，其合骨，其荣华在头发，其腑为三焦和膀胱，其日为壬癸，其时为亥子，其经脉为足少阴经。这是黑色的对应关系。
颜色的对应不仅针对脏，也对应其腑；对应腑的，也对应其经脉。但必须区分部位的内外，察清气色的阴阳。五色的显现，没有不相呼应的。所谓对应，是正常的情况；不对应，是变化的情况。知道正常与变化，就知道生克关系；知道生克关系，就知道顺逆。五脏各有病证、声色、臭味，应当与气口（寸口脉）和明堂相应。其太过或不及，相生或相克的，都是病态。通过外在表现了解内在病变，根本原理就在于此。
Observing the Qi color of Mingtang (the nose), one takes the corresponding locations of the Zang-Fu organs on the face as the substance, and the diagnostic method of Qi color as the function. Therefore, observing them separately allows one to recognize their normal state; consulting them collectively allows one to understand their variations. However, investigating these normals and variations to trace their origins and endings essentially does not depart from the principle of Yin and Yang.
Yin and Yang are the Way of Heaven and Earth, the general principles of all things, the parents of change, the beginning of life and death, and the residence of spiritual enlightenment. Thus, speaking of the Five Colors separately: Green belongs to Shaoyang (Lesser Yang), flourishing in Spring; Red belongs to Taiyang (Greater Yang), flourishing in Summer; White belongs to Shaoyin (Lesser Yin), flourishing in Autumn; Black belongs to Taiyin (Greater Yin), flourishing in Winter; Yellow belongs to Central Earth, residing in the four seasons, and flourishing in Late Summer.
Speaking of the six parts: External, upper, and left belong to Yang; Internal, lower, and right belong to Yin. Speaking of the "Ten Methods": Floating, clear, excessive, scattered, and lustrous belong to Yang; Deep, turbid, slight, condensed, and dull belong to Yin. Thus, Qi and color appear together, and locations are cross-referenced, resulting in an interweaving of Yin and Yang, with Yang within Yin and Yin within Yang. This is the general outline of Yin and Yang.
Regarding the Dao of Yin and Yang: Yang is clear, Yin is turbid; Yang ascends, Yin descends; Yang is hot, Yin is cold; Yang is active, Yin is quiet; Yang is external, Yin is internal; Yang is superior, Yin is inferior; Yang is left, Yin is right; the Path of Yang is solid, the Path of Yin is empty; Yang is often in excess, Yin is often deficient. Therefore, colors appearing in Yang conditions are easy to treat; those appearing in Yin conditions are difficult to heal. In exogenous diseases, if a Yin disease presents with Yang colors, it is easy to treat; if a Yang disease presents with Yin colors, it is difficult to heal. In endogenous injuries, if a Yang disease presents with Yin colors, it is easy to treat; if a Yin disease presents with Yang colors, it is difficult to heal.
All these principles of Yin and Yang can be consulted by combining Qi color and location, or by correlating Zang-Fu organs and symptoms. The *Yi Zhuan* (Commentaries on the Book of Changes) states: "One Yin and one Yang is called the Dao; unpredictable changes of Yin and Yang are called Shen (Spirit/Divinity)." The *Neijing* (Inner Canon) states: "Those who possess Shen prosper; those who lose Shen perish." The changes of Yin and Yang are integrated through this single principle.
I have examined the observation methods in the *Neijing*, believing that the Five Colors manifest externally, while the Five Zang organs correspond internally, just as roots correspond to branches. Color, pulse, form, and flesh must not be disconnected. Thus, where there is disease, there must be color; internal and external influence each other, like a shadow following a form, or a drum responding to a beat. From afar, one inspects the exterior to estimate the interior; from near, one inspects the interior to deduce the exterior. The manifestation of the Five Colors never fails to correspond. Why say this?
The Liver belongs to Wood in the East, communicating with Wind Qi, corresponding to the season of Spring, opening into the Eyes, associated with the emotion of Anger, manifesting in variation as abnormal speech, storing Hun (Ethereal Soul), its pulse is Xian (Wiry), its sound is Hu (calling out), its pitch is Jue (Jue note), its odor is Sao (fishy/foul), its taste is Suan (sour), its fluid is Qi (tears), it harmonizes with Sinews, its luster appears in the Nails, its paired Fu organ is the Gallbladder, its days are Jia and Yi, its hours are Yin and Mao, its meridian is the Foot Jueyin Meridian. This is the correspondence of Green.
The Heart belongs to Fire in the South, communicating with Heat Qi, corresponding to the season of Summer, opening into the Tongue, associated with the emotion of Joy, manifesting in variation as belching, storing Shen (Spirit), governing Blood, its sound is Xiao (laughter), its pitch is Zhi (Zhi note), its odor is Jiao (burnt), its taste is Ku (bitter), its fluid is Han (sweat), it harmonizes with Vessels, its luster appears in the Complexion, its paired Fu organ is the Small Intestine, its days are Bing and Ding, its hours are Si and Wu, its meridian is the Hand Shaoyin Meridian, its pericardium is the Hand Jueyin (Pericardium). This is the correspondence of Red.
The Spleen belongs to Earth in the Center, communicating with Dampness Qi, corresponding to the season of Late Summer, opening into the Mouth, associated with the emotion of Pensive thought, manifesting in variation as swallowing, storing Yi (Intellect), its pulse is Huan (Moderate), its sound is Ge (singing), its pitch is Gong (Gong note), its odor is Xiang (fragrant), its taste is Gan (sweet), its fluid is Xian (saliva), it harmonizes with Flesh, its luster appears in the Lips, its paired Fu organ is the Stomach, its days are Wu and Ji, its hours are Chen, Xu, Chou, and Wei, its meridian is the Foot Taiyin Meridian. This is the correspondence of Yellow.
The Lung belongs to Metal in the West, communicating with Dryness Qi, corresponding to the season of Autumn, opening into the Nose, associated with the emotion of Grief, manifesting in variation as coughing, storing Po (Corporeal Soul), governing Qi, its pulse is Mao (Hairy), its sound is Ku (crying), its pitch is Shang (Shang note), its odor is Xing (raw fishy), its taste is Xin (pungent), its fluid is Ti (nasal mucus), it harmonizes with Skin, its luster appears in Body Hair, its paired Fu organ is the Large Intestine, its days are Geng and Xin, its hours are Shen and You, its meridian is the Hand Taiyin Meridian. This is the correspondence of White.
The Kidney belongs to Water in the North, communicating with Cold Qi, corresponding to the season of Winter, opening into the Ears, associated with the emotion of Fear, manifesting in variation as yawning, storing Zhi (Will), its pulse is Shi (Stone-like), its sound is Shen (groaning), its pitch is Yu (Yu note), its odor is Fu (putrid), its taste is Xian (salty), its fluid is Tuo (spittle), it harmonizes with Bones, its luster appears in the Hair, its paired Fu organs are the Sanjiao (Triple Burner) and Bladder, its days are Ren and Gui, its hours are Hai and Zi, its meridian is the Foot Shaoyin Meridian. This is the correspondence of Black.
The correspondence of color applies to the Zang organs, and also to their paired Fu organs; the correspondence to Fu organs also applies to their meridians. One must only distinguish the internal and external locations and inspect the Yin and Yang of the Qi color. The manifestation of the Five Colors never fails to correspond. The correspondence represents the normal state; non-correspondence represents variation. Knowing the normal and the variable allows one to know the generating and overcoming relationships; knowing the generating and overcoming relationships allows one to know the compliant and rebellious patterns. Each of the Five Zang organs has specific disease manifestations, sounds, colors, odors, and tastes, which should correspond to the Qikou (Radial Pulse) and Mingtang. Excess or deficiency, generation or overcoming, are all pathological. Understanding the interior through the exterior is based on this principle.