Sayyiduna Jabir (may Allah be pleased with him) said: When we had entered ihram, we would also wear garments in which we had not entered ihram, and we would wear cloth dyed with red clay (mumashshaq); it is only clay.
It is narrated from Ikrimah (may Allah have mercy on him), the freed slave of Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both), that the Prophet (peace and blessings be upon him) changed his two garments at al-Tan'im while he was in ihram. Abu Dawud mentioned it in al-Marasil.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9073