It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that a man asked the Prophet (peace and blessings be upon him): O Messenger of Allah! After entering into Ihram, which clothes can we wear? The Prophet (peace and blessings be upon him) said: "You cannot wear a shirt, trousers, turban, or leather socks, except if someone does not find shoes. Whoever does not find shoes should cut the leather socks below the ankles and wear them. Similarly, a cap or any cloth that has been dyed with wars grass or saffron, the person in Ihram cannot wear that either."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5325
Hadith Gradingحکم دارالسلام:إسناده صحيح ، خ : 5794.