From wherever Islam has grown, one fundamental principle is believed and that is that discriminatory exclusion based on race is alien to Islam. This is understandable given that belief in the Oneness of Allah leads to a belief that all humanity are “equal” before Him i.e. He is the Lord and Sovereign, everyone else is a creation of His.
Allah states in the Quran in Surah al-Hujurat v13:
يَا أيُّهَا النَّاسُ إِنَّا خَلَقْنَاكُم مِّن ذَكَرٍ وَاُنثَی وَجَعَلْنَاكُمْ شُعُوبًا وَقَبَائِلَ لِتَعَارَفُوا
إِنَّ أكْرَمَكُمْ عِندَ اللَّهِ أتْقَاكُمْ إِنَّ اللَّهَ عَلِيمٌ خَبِيرٌ
Oh Humankind! We have created you from males and females and have made you into people شُعُوبًا and tribes قَبَائِلَ that you may know one another. Indeed the noblest of you أكْرَمَكُمْ amongst you before Allah are the most pious of you أتْقَاكُمْ. Indeed Allah is All Knowing and All Seeing.
Why was this ayah revealed? After the conquest of Makkah, the Prophet (SAW) asked Bilal (RA) to call the Adhan. Bilal was a black slave who was freed by Abu Bakr from the hands of Umayyah bin Khallaf prior to the Migration. A group of 3 new Muslims (become Muslim at the time of the Conquest of Makkah) saw this.
One remarked how he was happy that his parents (from the idol worshippers of Makkah) were not here to see this “disgusting sight”.
Another found it remarkable that the Prophet (SAW) could find no one else besides a black person to call the Muslims to prayer.
The third, Abu Sufyan, didn’t correct these other two but chose to reserve judgement, lest Allah reveal a verse to the Prophet (SAW) about this.
Indeed a verse was revealed to show how these 3 Arabs discriminated against a black person. Allah informs humans (not just the believers) that He only uses piety to judge between the believers. Calling the Muslims to prayer is a huge honour and the one who is chosen for this job must possess that level of piety which the others do not.