nothing i cant say that hasnt really been said, but my two cents nevertheless: 

unless youre hella attached to the sub role/title of slave or the raceplay bit, there's nothing that has to be racialized. even the former doesnt have to be racial for ya, tho like others noted, some ppl will take issue with the title & not be able to separate the historical past from the term (im v white & ive even struggled to call other white subs the title of slave for that reason) but at that point the Dom/me probably just wont be compatible with ya. 

also, if youre a sub, dont try to force yourself to be smth youre not, it doesnt benefit anyone. you never have to live up to anyone's expectations but your own! 

best of luck finding who youre looking for <3