I think India can retain its unique culture. Even several hundreds of years of British colonial rule cannot abolish native culture, nobody can! But India should also feel lucky that Britain is not barbarians like Manchu that would force you to change hairstyle and clothing.
I think it depends on the religiosity of a society. The more religious a community, the tendency they retain their ethnic regalia. For example, most societies in the Middle East are religious and thus they retain their clothing preference. If we examine Ultra-Orthodox Jews, they , too, retain very conservative style clothing. The Amish , Menonnite communities in the United States, which are religious communities and also retain their unique regalia. Perhaps one can attribute the ethnic regalia of many South Asian societies due to their religious nature as well; be it the Hindus in India, or the Muslims in Bangladesh and Pakistan.
yes, we have, in face, in ancient time, japan learnt all from China, like building, politic system, chinese characters, and costume. Kimono is origined from Chinese Hanfu, from Wu region, now this region is Suzhou, in Jiangsu Province, so Kimono is also called Wufu, means from Wu region.
Japanese Geisha was also origined from China, Tang Dynasty. here is the dance of ancient china Tang Dynasty , which evolved in to geisha in japan later
Xie Xie @Andrei !