Tirmidhi

Abu Hurairah (may Allah be pleased with him) reports that a man from Banu Fazara came to the Prophet (peace and blessings of Allah be upon him) and said: "O Messenger of Allah! A black child has been born to my wife." The Prophet (peace and blessings of Allah be upon him) asked him: "Do you have camels?" He said: "Yes." He asked: "What color are they?" He said: "Red." He asked: "Is there any grayish one among them?" He said: "Yes, there is a gray one among them." He asked: "Where did that come from?" He said: "Perhaps it inherited it from some ancestor." The Prophet (peace and blessings of Allah be upon him) said: "Perhaps this boy has inherited it from some ancestor and is black in color."

Imam Tirmidhi says: This hadith is Hasan Sahih.