It`s all about business.
If the foreigner is blond with blue eyes, the school may get more money from students` parents. I couldn`t get a job last year at a public college, because of the reason mentioned above. A girl from Uzbekistan was accepted there instead. ( blond with blue eyes ).
Otherwise, one can`t say Chinese are racist. Black people, Indians and Chinese from Singapore are treated in the same way like whites on the streets and in public places.
Just, when it`s about a teaching job,the leaders of some schools are very narrow minded.