Why are men not allowed to wear red colour clothes?

Answer

The reason why men are not allowed to wear red colour garments is the very same why Muslims are not allowed to consume meat if Allah's Name is not recited on the animal at the time of slaughter. And, that reason is that it is Allah's Command. When the Shariah (Qur'aan and Sunnah) issues a command, Muslims are obliged to say: "We hear and we obey." The quest for reasons is the effect of deficiency in Imaan.

The ahkaam of the Shariah were handed down and commanded by Rasulullah (sallallahu alayhi wasallam) without explaining the reasons. The reasons we or other Ulama proffer for the ahkaam are products of opinion. The Ulama say that red and all bright feminine colours are prohibited for males because such colours are meant for females just as gold and silver are permissible for only women. Feminine wear, feminine colours and feminine styles in general create feminine attitudes which are reprehensible for men, hence not permissible. Emulation of female styles and attitudes invoke Allah's Curse on the men.