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.

It should be known that Allah, may He be exalted and glorified, is Wise in His commands and prohibitions. He does not command anything except that which is in peoples’ best interests and He does not forbid anything except that which is harmful.