Zhu Mo is red. In ancient China, although red was a symbol of auspiciousness and celebration, at the same time, there was always a saying that "the calligraphy of Dan was unknown", both officially and privately, which meant that words written in red were generally unlucky. With the development of calligraphy in China, many people who have a deep understanding of calligraphy culture still follow the rules of using Zhu Mo with caution, and rarely see anyone writing in Zhu Mo in their daily life.