Why does the yellow calendar have a yellow word?

Almanac is a code of conduct followed by ancient emperors and a calendar promulgated by emperors, so people call it "imperial calendar"; After the Revolution of 1911, the imperial system was overthrown and the "imperial calendar" was rewritten as the "yellow calendar". The yellow calendar not only includes astronomy, meteorology, seasonal seasons, but also contains some taboos that people should abide by in their daily lives. Its contents guide the farming opportunities of working farmers in China, so it is also called farmers' calendar. The people of the Yellow Calendar are also commonly known as "general books". However, in Cantonese, because the word "Shu" in general books is homophone with the word "lose", it is also called "Tong Sheng" because of taboo.

Source: network link