green light

"The green light," Smithy was saying in horrified understanding.

He was aiming at the glowing crack where the green light was issuing.

I throw a green light; you keep it, and I get no light back.

For there, high up, was the green light of a distant rocket.

Light once more, green light with an odd shimmering quality to it.

But a pencil-point of the green light thinned and lengthened out.

And a green light came into his eye, for he was very angry at having to fight at all.

He waited outside the air-lock door for the green light to come on.

The green light came on, and the door of the air lock slid open.

He watched for the green light, but he saw only the red one.