I came to the Prophet ﷺ in Mecca while he was at al-Abtah in a small red leather tent. Bilal came out carrying water left over from the Prophet's ablution, and people were either receiving some of it or sprinkling it on themselves. Then the Prophet ﷺ came out wearing a red garment, and it is as if I can still see the whiteness of his shins... the rest of the hadith.
أتيت النبي ﷺ بمكة، وهو بالأبطح في قبة له حمراء من أدم قال: فخرج بلال بوضوئه فمن نائل وناضح قال: فخرج النبي ﷺ عليه حلة حمراء كأني أنظر إلى بياض ساقيه… الحديث.
Bukhari narrated it in the Book of Virtues (3566), and Muslim in the Book of Prayer (503:249), both through the route of Awn bin Abu Juhayfa, from Abu Juhayfa, who said, then he mentioned it.Abu Juhayfa's name was Wahb bin Abdullah Sawai . And "the hullah" refers to an upper garment and a lower garment of the same kind.