be in black and white

"This swan is so white," he thought, "and I am so black. It must be the happiest bird in the world."

“这只天鹅是那么白，”他想，“而我是那么黑。它一定是世界上最幸福的鸟了。”

In this square, you can see that if a cell is white, its left neighbor black, and its right neighbor white, then that cell will be black in the next step.

在这个方块中，可以看到如果细胞是白色的，它的左邻是黑色的，右邻是白色的，那么这个细胞在下一步将是黑色的。

They demanded that the agreement be written in black and white.

他们要求将这份协议用白纸黑字写下来。