The darkest hour is that before dawn.

黎明之前天最黑。

dark blue / green

深蓝/墨绿色

He wears a dark suit.

他穿着一套深色衣服。

a small, dark lady

身材娇小、皮肤黝黑的女士

Everything has its dark side.

任何事物都有其阴暗面。

before / after dark

天黑以前/以后

She was certainly not afraid of the dark.

她一点儿也不怕黑。