a very clear distinction, without any gradations.

非常清晰的区别，没有任何过渡;非黑即白，黑白分明的

Don't debate me about it. The rules are black and white, and you broke them.

别跟我争论这件事。规则是黑白分明的，而你打破了它们。

He tended to view everything as a black and white issue-it was either right or wrong-whereas his partner always found gray areas .

他倾向于把所有事情都看成是黑白分明的——不是对就是错——而他的伴侣总是能找到灰色地带。

It's not a black-and-white issue.

这不是一个非黑即白的问题。