It was narrated from Salamah bin Nubait that his father said:

"I saw the Messenger of Allah delivering a Khutbah on the day of Arafat atop a red camel."
Chpater 200. Delivering A Short Khutbah In 'Arafat

أَخْبَرَنَا مُحَمَّدُ بْنُ آدَمَ، عَنِ ابْنِ الْمُبَارَكِ، عَنْ سَلَمَةَ بْنِ نُبَيْطٍ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ ﷺ يَخْطُبُ يَوْمَ عَرَفَةَ عَلَى جَمَلٍ أَحْمَرَ .