Hadith - Al-Tirmidhi 4623, Narrated 'Aisha, r.a.
Allah's Messenger (peace be upon him) was questioned about Waraqah and Khadijah said to him, "He believed in you, but died before you appeared as a prophet." Allah's Messenger (peace be upon him) then said, "I was shown him in a dream, wearing white clothes, and if he had been one of the inhabitants of Hell he would have been wearing different clothing." [Ahmad and Tirmidhi transmitted it]
Hadith - Sahih Al-Bukhari 7.717, Narrated Abu Dharr, r.a.
I came to the Prophet while he was wearing white clothes and sleeping....
Hadith - Sahih Al-Bukhari 7.705, Narrated 'Aisha, r.a.
When Allah's Apostle died, he was covered with a Hibra Burd (green square decorated garment).
Hadith - Sunan of Abu Dawood, Narrated Abu Rimthah, r.a.
I went with my father to the Prophet (peace be upon him) and saw two green garments over him.
It is permissible to wear red clothes if the red is combined with another colour; it is not permissible to wear plain red, because the Prophet (saaws) forbade doing so.
The hadith which forbid wearing plain red
From al-Baraa’ ibn ‘Aazib (may Allah be pleased with him): “The Prophet (saaws) forbade us to use soft red mattresses and qasiy – garments with woven stripes of silk.” (Narrated by al-Bukhaari, 5390)
From Ibn ‘Abbaas, who said: “I was forbidden (to wear) red garments and gold rings, and to recite Qur’aan in rukoo’.” (Narrated by al-Nasaa’i, no. 5171. Imam Albaani said: its isnaad is sahih. Saheeh Sunan al-Nasaa’i, 1068).
From ‘Abd-Allaah ibn ‘Amr ibn al-Aas (may Allaah be pleased with them both), who said: “A man passed by the Prophet SAWS wearing two red garments and greeted him with salaam, but he SAWS did not return the greeting.” (Narrated by al-Tirmidhi, no. 2731; Abu Dawood, no. 3574. Al-Tirmidhi said: this hadeeth is hasan ghareeb with this isnaad). According to the scholars, the meaning of this hadith is that the Prophet SAWS disliked the wearing of garments dyed with safflower (the red dyestuff obtained from safflowers), but he had no objection to garments dyed with clay or other substances, so long as it was not dyed with safflower. This hadeeth was classed as da’eef by al-Albaani (Da’eef Sunan Abi Dawood, 403; Da’eef Sunan al-Tirmidhi, 334. He said: its isnaad is da’eef).
Hadith which may be understood to mean that it is permissible to wear red if it is mixed with another colour
From Hilaal ibn ‘Aamir from his father, who said: “I saw the Messenger of Allaah SAWS in Mina, giving a khutbah sitting on his mule, wearing a red cloak, and ‘Ali was in front of him, repeating what he said (in a loud voice, so that the people could hear).” (Narrated by Abu Dawood, no. 3551; classed as sahih by al-Albaani – Sahih Sunan Abi Dawood, 767).
The hadeeth of al-Baraa’ ibn ‘Aazib (may Allaah be pleased with him) who said: “The Messenger of Allah SAWS was of average build. I saw him in a red hullah, and I never saw anyone more handsome than him.” (Narrated by al-Bukhaari, no. 5400; Muslim, 4308).
From al-Baraa’, who said: “I never saw anyone who has hair wearing a red hullah and looking more handsome than the Messenger of Allah SAWS (peace and blessings of Allah be upon him). He had hair down to his shoulders, he was broad-shouldered and was neither short nor tall.” (Narrated by al-Tirmidhi, no. 1646. He said: in this chapter there is a report from Jaabir ibn Samurah and Abu Rimthah and Abu Juhayfah. This hadeeth is hasan saheeh…)
From al-Baraa’ who said: “The Messenger of Allaah SAWS had hair down to his earlobes. I saw him wearing a red hullah, and I have never seen anyone more handsome than him.” (Narrated by Abu Dawood, no. 4072; Ibn Maajah, no. 3599. Classed as sahih by Albaani – Saheeh Sunan Abi dawood, 768).
Al-Bayhaqi narrated in al-Sunan: “[The Prophet] SAWS used to wear a red cloak on Eid.”
What is meant by a red hullah is a suit of two Yemeni garments which are woven with red and black stripes, or red and green stripes. It is described as red because of the red stripes in it.
This is the view of a number of scholars, such as al-Haafiz Ibn Hajar (Fath al-Baari Sharh ‘ala Sahih al-Bukhari, no. 5400) and Ibn al-Qayyim (Zaad al-Ma’aad, 1-137). And Allaah knows best indeed.