Sayyiduna Abdullah bin Umar (may Allah be pleased with him) says that the Prophet (peace and blessings be upon him) forbade the one in ihram from wearing a garment dyed with wars or saffron, and said: "Whoever cannot find sandals may wear leather socks (khuffs), cutting them below the ankles."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9064