《明史·志·卷四十三》
洪武三十年，命令退休官员的服色与在职官员一样，如果朝觐庆贺、拜谢皇帝的恩德、面见辞别皇帝，一样穿戴官服。
三十年，令致仕官服色与见任同，若朝贺、谢恩、见辞，一体具服。
In the 30th year of Hongwu, retired officials were ordered to wear the same costumes as serving officials. If they came to the court to celebrate, thank the emperor, or say goodbye to the emperor, they should wear official uniforms.