Muwatta Malik, Book 20, Hadith 717 (In-Book) ⓘ

Yahya related to me from Malik from Nafi that he had heard Aslam, the mawla of Umar ibn al-Khattab, telling 'Abdullah ibn Umar that Umar ibn al-Khattab once saw a dyed garment on Talha ibn Ubaydullah while he was in ihram and Umar said, "What is this dyed garment, Talha?", and Talha said, "Amir al-muminin, it is only mud.'' Umar said, "You and your like are taken by people as imams, and if an ignorant man were to see this garment he would say that Talha ibn Ubaydullah used to wear a dyed robe while he was in ihram. So do not wear any form of dyed clothes."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّهُ سَمِعَ أَسْلَمَ، مَوْلَى عُمَرَ بْنِ الْخَطَّابِ يُحَدِّثُ عَبْدَ اللَّهِ بْنَ عُمَرَ أَنَّ عُمَرَ بْنَ الْخَطَّابِ، رَأَى عَلَى طَلْحَةَ بْنِ عُبَيْدِ اللَّهِ ثَوْبًا مَصْبُوغًا وَهُوَ مُحْرِمٌ فَقَالَ عُمَرُ مَا هَذَا الثَّوْبُ الْمَصْبُوغُ يَا طَلْحَةُ فَقَالَ طَلْحَةُ يَا أَمِيرَ الْمُؤْمِنِينَ إِنَّمَا هُوَ مَدَرٌ ‏.‏ فَقَالَ عُمَرُ إِنَّكُمْ أَيُّهَا الرَّهْطُ أَئِمَّةٌ يَقْتَدِي بِكُمُ النَّاسُ فَلَوْ أَنَّ رَجُلاً جَاهِلاً رَأَى هَذَا الثَّوْبَ لَقَالَ إِنَّ طَلْحَةَ بْنَ عُبَيْدِ اللَّهِ كَانَ يَلْبَسُ الثِّيَابَ الْمُصَبَّغَةَ فِي الإِحْرَامِ فَلاَ تَلْبَسُوا أَيُّهَا الرَّهْطُ شَيْئًا مِنْ هَذِهِ الثِّيَابِ الْمُصَبَّغَةِ ‏.‏