".....Our subject is Traffic Lights. A traffic light is one of the most common things which you will find on a road. It is an invention made for organizing the traffic flow and every driver must obey it. If the light goes green you may pass, if it’s red you have to halt and if it’s yellow then you must behave with caution". "A person who drives daily can’t imagine driving from home to office without a traffic light. But do you know there was an era when there was no concept of traffic lights? Surely this was the same period when there was no concept of cars as well, however, let’s just pretend I didn’t say that". "Let’s come back to the initial para of my article, as I said there are a few clear rules which one has to follow every time you get in the car. Traffic lights are same all around the world. They have the same three colors in every country on this planet. Green signifies for “Go”, red means “Stop” and yellow or orange means “Be Careful”. "But here is the question which bothers me the most, why are all the traffic lights green, red and yellow? Why aren’t they some other color? There are many pretty colors like purple, magenta, pink, turquoise etc. There are many arguments on this subject, but before I take you to the main topic, let’s take a short glimpse at the history of traffic lights".