Why is the national flag red?

The Resolution of China People's Political Consultative Conference on the Capital, Calendar, National Anthem and National Flag of People's Republic of China (PRC) and the Measures for Flag Making adopted by the CPPCC Presidium stipulate that:

The national flag of China people * * is a five-star red flag, rectangular and red, symbolizing the revolution, and the ratio of length to width is three to two. There are five yellow five-pointed stars on the upper left of the flag, symbolizing the great revolutionary unity under the leadership of the * * * production party. The stars use yellow to symbolize the light on the red earth.

1On April 23rd, 949, Nanjing was liberated by the People's Liberation Army and the reactionary Kuomintang regime was destroyed. At the China People's Political Consultative Conference held in September, the five-star red flag was determined as the national flag of the people of China. The designer of the national flag is Zeng Song Lian.

Extended data:

The five stars in the upper left corner of the national flag are yellow, indicating the light on the red ground. The five five-pointed stars on the national flag and their relationship symbolize the great unity of the revolutionary people under the leadership of the Communist Party of China.

The big five-pointed star in the national flag represents the China * * * production party, and the four small five-pointed stars represent workers, peasants and the national bourgeoisie. The national flag is red, symbolizing the revolution, and the stars are yellow, indicating that the Chinese nation is yellow.

The five five-pointed stars are connected with each other, alternating in density, symbolizing the great unity of the people of China. Every little star has a sharp corner facing the center of the big star, which shows the centripetal significance of the people to the party.

References:

Baidu Encyclopedia-China People and the National Flag