The general level of intelligence of the owners and the ones who are running the school are probably on par with albino living creatures spanning all spectrum of species. A combination of cataracts and glaucoma also probably contributes to the mental derangement of these folks. Therefore they only want to hire people who they can see. Since they are so reverse color blind they might as well put up a board saying, "We want white crocodiles and polar bears to enjoy the sunny, southern climate of Fujian!"