Railway traffic lights and their meanings; colors and meanings of railway traffic lights.

The display colors of railway signals in China are composed of basic colors and auxiliary colors. There are three basic colors: red, yellow and green. Red: stop; Yellow: Pay attention or slow down; Green: Run at the specified speed. Auxiliary colors are mainly moonlight, blue, transparent white and purple. Moon white and blue are mainly used for shunting signals, indicating shunting permission and shunting prohibition respectively. Transparent white is used for signal indicator, and purple is only used for turnout indicator.

Railway signal is to use the color, shape and position of specific objects, or use instruments and audio equipment to convey information about the running status of locomotives and vehicles, the status of running equipment, and running instructions and commands. Railway signal is the general name of technical equipment to ensure the safety of trains and shunting operations, improve the passing capacity of stations and sections and the ability of train disintegration, and improve the working conditions of operators.