Normal operation: green; shutdown and maintenance: blue; equipment deactivation: blue; equipment failure: yellow; equipment storage: red.
The International Organization for Standardization (ISO) and many countries have strict regulations on the use of safety colors. Our country has formulated national standards for safety colors. It is stipulated that four colors, red, yellow, blue and green, should be used as the national safety colors. Generally speaking, red mostly refers to prohibition, yellow mostly means attention and warning, blue means instructions and must be followed, and green means passage, safety and information reference, so equipment status signs are also classified accordingly.