Those green patches on the drive- would these fellows use green to indicate danger?

Horizontal, indicating danger or warning of danger; at night indicates a red light.

The red flag indicates danger: never enter the water when the red flag is flying.

I am no fit replacement, yet if the Oracle indicates danger for me, she is rightfully concerned.

A louder, higher pitched twitter is used to indicate danger.

During a difficult delivery, Koch called for a "Code pink" emergency, indicating danger to the life of mother and/or child.

Red is widely used to indicate danger.

The warning symbol at top-right indicates what danger the chemical presents.

He wasn't sure yet why, but his instincts warned him that the red seal indicated danger.

If I'm carrying a copy of Life magazine don't make contact: it will indicate danger.