Huangdi Neijing pointed out that five colors match five flavors, five flavors enter the five internal organs, blue nourishes the liver, red nourishes the heart, yellow nourishes the spleen and stomach, white nourishes the lungs and black nourishes the kidney. Proper conditioning of the five internal organs is helpful to regulate the balance of the five internal organs.

Red nourishes the heart, bitter enters the heart, and the heart is the main pulse. Some red foods can enter the heart and blood after entering the human body, which has the functions of benefiting qi and enriching blood, promoting blood circulation and maintaining heart health. Most bitter foods can make excess heart fire excreted, clearing heart and improving eyesight, but most bitter foods are cold, and those with spleen and stomach deficiency should eat less.

Red food for nourishing blood: medlar, red dates and cherries;

Clear heart and bitter food: bitter gourd, lettuce and lotus plumule;

Green nourishing the liver, sour taste entering the liver, storing blood in the liver, promoting hair growth, has the characteristics of stopping diarrhea, liking articles and being depressed, and plays an important role in regulating the whole body qi. Some green foods have the function of dredging liver-qi, and most sour foods have the functions of consolidating exterior surface, stopping sweating, astringing qi and nourishing yin.

Green food with liver qi: spinach, broccoli and celery;

Sour food commonly used for nourishing yin: ebony, citrus, lemon, etc.

Yellow benefits the spleen, and sweet taste enters the spleen, which is responsible for transporting and regulating blood, digesting, absorbing and transporting foreign nutrients. Some yellow foods can strengthen the spleen and nourish the stomach, and most sweet foods can regulate the spleen and stomach.

Yellow sweet food for strengthening the spleen: pumpkin, corn and sweet potato.

White moistens the lungs, pungent taste enters the lungs, and the lungs control qi, the main propaganda and the main breathing. White food has the functions of clearing away lung heat, moistening lung and nourishing lung. When pungent taste enters lung, it can spread lung qi and promote qi and blood circulation.

White food for nourishing lung: white radish, tremella and yam.

Hot and spicy food: ginger, onion and garlic.

Black tonifies the kidney, salty taste enters the kidney, and the kidney stores essence and produces marrow, which is the main growth and reproduction.

Black food for tonifying kidney: black rice, black sesame and black beans.

Salty food for tonifying kidney: kelp, laver and oyster.

In recent years, the popular "rainbow principle", five-color food provides all kinds of nutrients needed by the human body, but there is a limit to everything, and many beneficial foods must not be eaten excessively.