The Prophet ﷺ forbade Muhrims to wear clothes dyed with Wars or saffron. (Using translation from Bukhārī 5847)  

«نَهَى رَسُولُ اللهِ ﷺ أَنْ يَلْبَسَ الْمُحْرِمُ ثَوْبًا مَصْبُوغًا بِزَعْفَرَانٍ أَوْ بِوَرْسٍ»  

‘Abd Allaah bin Umar said A man asked the Apostle of Allaah ﷺ What clothing one should put on if one intend to put on ihram? He said He should not wear shirts, turbans, trousers, garments with head coverings and clothing which has any dye of waras or saffron; one should not put on shoes unless one cannot get sandals. If one cannot get sandals, one should wear the shoes, in which case one must cut them to come below the ankles. (Using translation from Abū Dāʾūd 1823)  

سُئِلَ رَسُولُ اللهِ ﷺ مَا يَلْبَسُ الْمُحْرِمُ مِنَ الثِّيَابِ قَالَ «لَا يَلْبَسُ الْقَمِيصَ وَلَا الْبُرْنُسَ وَلَا السَّرَاوِيلَ وَلَا الْعِمَامَةَ وَلَا ثَوْبًا مَسَّهُ وَرْسٌ وَلَا زَعْفَرَانُ وَلَا خُفَّيْنِ إِلَّا لِمَنْ لَمْ يَجِدُ نَعْلَيْنِ فَإِنْ لَمْ يَجِدْ نَعْلَيْنِ فَلْيَقْطَعْهُمَا حَتَّى يَكُونَا أَسْفَلَ مِنَ الْكَعْبَيْنِ»