The sun is composed of seven colors of red, orange, yellow, green, cyan, blue, and purple, and their wavelengths and deflection angles are different. Sunlight illuminates the object, and various objects have different absorbing and reflecting abilities for light of different wavelengths, and various colors are formed. In visible light, red light has the longest light wave and the smallest deflection angle, which easily passes through water layers, raindrops, dust and fog. Orange and yellow light are not afraid of obstruction and can penetrate the above objects. Therefore, the fire truck is painted red in order to survive in the foggy weather, in a dusty environment or in a stormy storm, so that people can see it from afar and give way to it so that it can complete the fire fighting and rescue mission as soon as possible.
Fire trucks in most countries are red. Because it is the most eye-catching, it can be seen from a long distance. However, according to a survey conducted by the New York Department of Transportation, the red fire trucks have 100,000 trips and 32 incidents. If the fire truck is painted in a more vivid yellow, every 100,000 trips, the anecdote is only 14.5 times, a drop of more than half. Because the light color makes the outline of the car appear larger, it has a feeling of being closer to itself, which is good for traffic safety. So they advocated painting the fire truck yellow. However, the fire department is firmly opposed to this, because the yellow makes people emotionally stable, which will reduce the efficiency of fire fighting, and the red is more exciting and exciting.