Allow whites to celebrate their ancestry and their culture then you wont have so many misguided people appropriating others clothing and fashions. As long as the failed multicultural experiment continues 'cultural appropriation' is inevitable.
Any race can practice culture appropriation. For me, culture appropriation is using something from a culture without giving credit when due or just claiming it as your own without giving acknowledgement to the "creators". I didn't use to believe in. But let's think of it this way... so let's say you have a marginalized group of people who created a specific style of dance or slang or style that they created of to express themselves in a society that mocked them. So lets say people liked some aspects of the culture and decided to use them. So the people incorporate in their own culture but don't want to acknowledge the "creators" but bash the creators and claimed the culture as their own.
This reminds me of some women using slang created by black gay men from NY but still want to bash gay men. Or people using traditional clothing as a Halloween costume when actual people dress in those clothing for significant events and represent who they are.
I'm not saying I think college campuses cafes should be closed down for serving sushi or anything like that.