Is Wearing Red Haram in Islam?
Question

I've heard that it's wrong for men to wear red. Is this true?
Praise be to Allah.Can men wear red?
The scholars differed concerning the ruling on men wearing red clothes, and different hadiths have been narrated concerning that. Some hadiths indicate that wearing red is forbidden, whilst others indicate that it is permitted. 
How to reconcile between hadiths about wearing red clothes?
It is possible to reconcile between them – praise be to Allah – because the hadiths do not contradict with one another in fact, as the source is one. The correct view concerning this matter is that the hadiths can be reconciled in the following manner:
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 (peace and blessings of Allah be upon him) forbade doing so.
The hadiths which forbid wearing plain red 
There follows a discussion of some of the hadiths on this issue:

The hadiths which forbid wearing plain red.


From al-Bara ibn ‘Azib (may Allah be pleased with him): “The Prophet (peace and blessings of Allah be upon him) forbade us to use soft red mattresses and qasiy – garments with woven stripes of silk.” (Narrated by al-Bukhari, 5390)
From Ibn 'Abbas, who said: “I was forbidden (to wear) red garments and gold rings, and to recite Quran in ruku’.” (Narrated by al-Nasai, no. 5171. Imam al-Albani said: its isnad is sahih. Sahih Sunan al-Nasai, 1068
From ‘Abd-Allah ibn ‘Amr ibn al-As (may Allah be pleased with them both), who said: “A man passed by the Prophet (peace and blessings of Allah be upon him) wearing two red garments and greeted him with salam, but he (peace and blessings of Allah be upon him) did not return the greeting.” (Narrated by al-Tirmidhi, no. 2731; Abu Dawud, no. 3574. Al-Tirmidhi said: this hadith is hasan gharib with this isnad). According to the scholars, the meaning of this hadith is that the Prophet (peace and blessings of Allah be upon him) 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 hadith was classed as da’if by al-Albani (Da’if Sunan Abi Dawud, 403; Da’if Sunan al-Tirmidhi, 334. He said: its isnad is weak).

Hadiths which permit wearing red if it is mixed with another colour

Hadiths which may be understood to mean that it is permissible to wear red if it is mixed with another colour:


From Hilal ibn ‘Amir from his father, who said: “I saw the Messenger of Allah (peace and blessings of Allah be upon him) 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 Dawud, no. 3551; classed as sahih by al-Albani – Sahih Sunan Abi Dawud, 767).
The hadith of al-Bara ibn ‘Azib (may Allah be pleased with him) who said: “The Messenger of Allah (peace and blessings of Allah be upon him) was of average build. I saw him in a red hullah, and I never saw anyone more handsome than him (peace and blessings of Allah be upon him).” (Narrated by al-Bukhari, no. 5400; Muslim, 4308).
From al-Bara, who said: “I never saw anyone who has hair wearing a red hullah and looking more handsome than the Messenger of Allah (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 Jabir ibn Samurah and Abu Rimthah and Abu Juhayfah. This hadith is hasan sahih…)
From al-Bara who said: “The Messenger of Allah (peace and blessings of Allah be upon him) 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 Dawud, no. 4072; Ibn Majah, no. 3599. Classed as sahih by al-Albani – Sahih Sunan Abi Dawud, 768).
Al-Bayhaqi narrated in al-Sunan: “[The Prophet] (peace and blessings of Allah be upon him) 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-Hafiz Ibn Hajar (Fath al-Bari Sharh ‘ala Sahih al-Bukhari, no. 5400) and Ibn al-Qayyim (Zad al-Ma’ad, 1-137). 
For more, please see these answers: 13213 , 171834 , 926 , and 126692 . 
And Allah knows best.