Do government departments have any regulations on promotional banners? Does the color of the font have any meaning?

Are the rules just some unwritten rules, not so rigid? As for the fonts and colors, the black, red, and white characters in bold and Song fonts are generally used!

Government agencies:

In a broad sense, it refers to all central and local legislative, administrative, judicial and bureaucratic agencies. Government agencies in the narrow sense only refer to central and local administrative agencies and bureaucratic agencies, that is, those state agencies that are established in accordance with national laws and enjoy administrative power and assume administrative functions. In our country, they are also called "national administrative agencies."