It seems to me whatever the capital wears the rest of the country wears (w/exception of U.S. and a few others)
Ex. If there is some hot new trend in Paris, most likely, the rest of the country will get into the "trend" or fashion.
That may not always be the case, but alot of times that happens.
Btw, I find the fashion in France to be very interesting. It's not my cup of tea, but it isn't bad either.
