Rules? Just some unwritten rules. Not that dead. As for fonts and colors, black, red and white characters in bold and song style are generally used!

Government agencies:

Broadly speaking, it refers to all legislative, administrative, judicial and bureaucratic institutions of the central and local governments. In a narrow sense, government agencies only refer to the central and local administrative organs and bureaucracies, that is, those state agencies established in accordance with state laws that enjoy administrative power and undertake administrative functions. In China, they are also called "state administrative organs".