Q:Given the following passage "Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded the following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City, Utah. Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red.", answer the following question. Note that the answer is present within the text. Question: What is the second reason given for why red was chosen as a color?
A:
its association with danger