It is going to be dark soon.

天快要黑了。

《新英汉大辞典》

A leatherback may be able to pick up some body heat by basking at the surface; its dark, almost black body color may help it to absorb solar radiation.

棱皮龟可以通过在水面上晒太阳来为身体获取热量；深色近乎黑色的身体颜色可以帮助它吸收太阳辐射。

youdao

It will be dark in fifteen minutes—and then let them follow us if they want to.

十五分钟后就天黑了——如果他们愿意，就让他们跟着我们吧。

youdao

It would be dark by then.

VOA: special.2010.05.01

But honestly, the right question is, will it be as dark as itself?

FORBES: Epic British Science Fiction Series 'Blake's 7' May Get a Remake

The music is tranquil, the pacing is whatever I want it to be, I can collect and horde, I can be a thief or assassin (all my killings are assassinations because I am of the Dark Brotherhood be it contract or not).

FORBES: Why Do Gamers Play One Game for Hundreds, Even Thousands of Hours?

That's because as the Earth moves around the Sun, it is moving into a stationary field of dark matter - and for half the year it will be moving against the tide of dark matter - just like driving into the rain.

BBC: Dark Matter: Experiment to shed light on dark particles