Sunan Abi Dawud 4064
Narrated Zayd ibn Aslam:
Ibn Umar used to dye his beard with yellow colour so much so that his clothes were filled (dyed) with yellowness. He was asked: Why do you dye  with yellow colour? He replied: I saw the Messenger of Allah (ﷺ) dyeing with yellow colour, and nothing was dearer to him than it. He would dye all his clothes with it, even his turban.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، حَدَّثَنَا عَبْدُ الْعَزِيزِ، - يَعْنِي ابْنَ مُحَمَّدٍ - عَنْ زَيْدٍ، - يَعْنِي ابْنَ أَسْلَمَ - أَنَّ ابْنَ عُمَرَ، كَانَ يَصْبُغُ لِحْيَتَهُ بِالصُّفْرَةِ حَتَّى تَمْتَلِئَ ثِيَابُهُ مِنَ الصُّفْرَةِ فَقِيلَ لَهُ لِمَ تَصْبُغُ بِالصُّفْرَةِ فَقَالَ إِنِّي رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَصْبُغُ بِهَا وَلَمْ يَكُنْ شَىْءٌ أَحَبَّ إِلَيْهِ مِنْهَا وَقَدْ كَانَ يَصْبُغُ بِهَا ثِيَابَهُ كُلَّهَا حَتَّى عِمَامَتَهُ ‏.‏