Why are traffic lights green,yellow and red and not any other colour?

Question

why cant it be pink purple and blue.why only red green and yellow.

Answer 1

Red is a color that gets attention. Yellow is a general "caution" color and green is a relaxing color.

Answer 2

In 1920 Police Officer William Potts addressed the chaotic traffic of Detroit, Michigan, by co-opting the red, amber, and green automatic traffic light system used on railroads. Around the same time, the prolific African American inventor Garrett Morgan devised and patented the precursor to the automatic traffic lights we use today.

Apparently the colors of red and green were standard in the electrical industry at the time. The makers of railroad signals and traffic lights simply adopted the familiar color scheme.

Answer 3

Because red has always meant stop. Green means go and yellow means go faster. lol. But in reality, I have to agree with Chad D.

Answer 4

that is the world wide accepted colors....here is a link for you to read     http://www.inspirationline.com/Brainteas...

Answer 5

if you are color blind you can tell the lights from one another