Red means no, stop, fire and danger, such as the emergency brake handle on the vehicle.
Yellow indicates caution and warning, such as the center line of the lane.
Blue indicates instructions and regulations that must be observed, such as traffic signs.
Green means traffic, safety and providing information, such as traffic and safety signal flags.
red
Red is very eye-catching, which makes people feel excited and stimulated psychologically. Red is not easy to be blocked by dust and fog, and it can still be recognized in far places, and the degree of attention is very high.
yellow
Yellow will make people feel brighter, brighter than red.
blue
The brightness of blue is not as high as other colors, but it is also obvious in direct sunlight. It can have a good visual effect with white.
green
Green represents life, freshness, vigor, youth and youthfulness, and has the feeling of peace, eternity, growth and security, so it is used as a safety reminder.
Meaning use
red
It means prohibition, stop, fire fighting and danger. Prohibited, stopped and dangerous devices, equipment or environment are marked in red. Such as prohibition signs, traffic prohibition signs, fire-fighting equipment, stop buttons and operating handles of parking and braking devices, limit position scales on instrument panels, exposed parts of rotating parts of machines, strips and characters of liquefied petroleum gas tankers, danger signal signs, etc.
yellow
It means to pay attention and warn. Devices, equipment or environments that need warning are marked in yellow. Such as warning signs, traffic warning signs, road traffic signs, pulley inner wall and its protective cover, grinder cover inner wall, stair front steps, protective railings, warning signal flags, etc.
blue
Indicates the instructions and rules that must be followed. Such as indicator signs, traffic signs, etc.
green
It means transportation, safety and providing information. Traffic or safety conditions can be marked in green. For example, it indicates traffic, machine start button, safety signal sign, etc.
Black and white are generally used as the contrast colors of safety colors, mainly used as the background colors of the above safety colors. For example, the background color on safety signs is usually white or black.
The above contents refer to Baidu Encyclopedia-Safety Color.