People's Republic of China (PRC)'s criminal law stipulates which colors of flags to use to crack down on illegal crimes.

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From the legal point of view, there is no clear stipulation, but it is expressed according to the customary practice or the entrusted meaning carried by the actor. Generally speaking, there are white characters on a black background and red characters on a white background. For example, there may be the word "murder" in black or red on the placard when executing the death penalty. I have also seen black characters on a red background, which also shows majesty.