Do muslim women have to follow the dress code?

It depends on the country. If its a theocratic state, then yes; more than likely no smiling, or looking at other men. Keep in mind that statistically most Muslims in the world aren't even Arab. For example, China has more Muslims than any single Islamic state. Indonesia, in Asia, has the most Muslims in the world, and they are a Democracy, not a Theocracy; therefore how they choose to cover themselves is optional. You also have to make the distinction between religion and culture. The veil or headscarf predates Islam many centuries and was worn in Persian societies and even European societies. When have you ever seen Mother Marry pictured without the veil? Never. :)