卖炭的掉在面缸里
mài​tàn​de​diào​zài​miàn​gāng​lǐ

cannot tell black from white

卖炭的掉在面缸里 賣炭的掉在麵缸裡 mài​tàn​de​diào​zài​miàn​gāng​lǐ
cannot tell black from white
(xiehouyu) To be unable to distinguish between right and wrong or good and evil. Literally "a charcoal seller falling into a flour vat", where the black of the charcoal and the white of the flour are mixed up.