Color

Safety Red identifies , &  (Electric Power.) 
Some common applications are fire protection, emergency egress, emergency stop bars, electrical switches and electric power facilities.

Safety Orange identifies an intermediate level of hazard, such as .
Commonly used to identify hazardous parts of machinery, on  signs or to indicate telecommunications facilities.

Safety Yellow identifies .
Common applications include alerting against unsafe practices, identifying physical hazards, personal protection messages, on signs, and to indicate petroleum pipelines.

Safety Blue identifies a Mandatory Action not directly associated with a hazard, such as facility policies, information, etc. Also used to indicate buried water pipelines.

Safety Green idenfities the location of safety equipment, first aid, egress, general safety information. Also used to indicate buried sewer pipelines.