Why are fire trucks red?

There's is no specific answer to this question but it is believed that fire trucks are red because of several reasons. These reasons are:

Most of the cars on the road were black in color and the only way the fire trucks could standout is to give them a different color and red happened to be the preferred color because it is highly visible in day light.

Many also believe that certain colors pass certain messages to people. Red is known to be a used as warning sign, danger sign and emergency sign. Since fire trucks are for emergencies, it is understandable why red is use on fire trucks.

It is also known that in the earliest days, fire departments were made up of unpaid volunteers. Red paint was the cheapest paint available so all the vehicles were painted red.