What does Zhu Yuanzhang mean by ordering Spring Festival couplets to be written in black on a red background?

Spring Festival couplets are very practical for painting and calligraphy in daily life. "The birth of Spring Festival couplets began in Ming Taizu." Zhu Yuanzhang first ordered the Spring Festival couplets to be written in red paper and black ink, and named them "Wan Nianhong" because "red" and "Zhu" have the same meaning. Zhu Yuanzhang's original intention was to pray for the long-term stability of the authoritarian regime. URL = 76 fnjjvlfn P5 cgyjwd _ _ gvjh H3 sibsyuu 6 TT 7 btu 0 otxpyejofvhfhnn 8 YY 7 sy jsh 8 faiouuic 19 eqldrbet 3 tzk 7 _ OmotrxihSI _ Jda