It's all dark outside.

Everything went black.

The room was so dark that we could see nothing at all.

The room was in complete darkness.

When she looked, he shut the door and locked her into the totally dark closet.

It was dark when he came in.

The sky was completely dark.

It was pitch black outside.

The house was as dark as dark.

At the moment that I thought I was having a premonition, suddenly everything went black.

It's totally dark outside.

It was a dark night.