Iran is asking its visitors to comply with a number of rules regarding clothing.
Wearing the headscarf is compulsory for women including foreign women, but color does not matter. The best is to provide light clothing and scarves in cotton, light colored especially in summer. They should also wear loose clothing such as a winter coat or a shirt in summer. In general, they must cover their arms and legs.
Makeup is allowed except in the holy places.
Men will not be able to wear shorts or bermuda shorts. They will also have to cover their arms in some holy places.
Please abide by these rules as soon as you land in Tehran, because your failure may be a source of trouble for you and your traveling companions.
Do not forget to take off your shoes at the entrance to the mosques and mausoleums.