Final answer:
The red and yellow discs indicate important information about the hazards associated with substances in a fire extinguishing system.
Step-by-step explanation:
The red and yellow discs in a fire extinguishing system indicate important information about the hazards associated with certain substances. The red diamond symbolizes the level of fire hazard, such as the temperature range for flash points.
The yellow diamond represents reactivity hazards, for example, how readily the substance can undergo a violent chemical change. These color-coded discs are part of the NFPA 704 Hazard Identification System, which provides safety information to help identify and handle hazardous substances.