White cement use a month will become a black seam, it was terrible.

白水泥使用一个月就会变成黑缝，难看死了。

youdao

Ceramic tile 10 million tick off seam can't use white cement, must choose special tick off seam an agent.

瓷砖勾缝千万不能用白水泥，一定要选择专用的勾缝剂。

youdao