Messenger of Allah ﷺ said, "You should listen to and obey, your ruler even if he was an Ethiopian (black) slave whose head looks like a raisin." (Using translation from Bukhārī 7142)

قَالَ رَسُولُ اللهِ ﷺ اسْمَعُوا وَأَطِيعُوا وَإِنِ اسْتُعْمِلَ عَلَيْكُمْ عَبْدٌ حَبَشِيُّ كَأَنَّ رَأْسَهُ زَبِيبَةٌ