The teachings of Shariah regarding clothing are very moderate. Shariah has not prescribed any specific clothing, but it has set the boundaries for clothing. The clothing that falls within these Shari'ah boundaries will be called Islamic (Shar'i) clothing. Those boundaries are:
Number (1): The clothing should not be so short, transparent, or tight that the body parts which are obligatory to cover become visible.
Number (2): The clothing should not be such that it resembles that of the disbelievers (Kuffar) and transgressors (Fussaq).
Number (3): The clothing should not exude arrogance and pride, extravagance, and luxury. However, while avoiding extravagance, luxury, and showing off, it is permissible to wear valuable clothing to please one's heart.
Number (4): A man's shalwar, tahband, and pajama should not be below the ankles.
Number (5): A man's clothing should not be of pure silk, because it is Haram (forbidden).
Number (6): Men should not wear women's clothing, and women should not wear men's clothing.
Number (7): Wearing completely red colored clothing is Makruh (disliked) for men. However, if there is a mixture of some other color, or if it has red stripes, then there is no harm. (Aham Masail / Vol: 1 / Pg: 143)