What colors does a CO detector change to when carbon monoxide fumes are present?

A carbon monoxide (CO) detector is designed to provide a clear visual indication of the presence of dangerous levels of carbon monoxide gas, which is a colorless and odorless hazardous material. When CO is detected, many detectors will change color as an alerting mechanism. Options B and C both reflect common color changes observed in CO detectors.

Specifically, yellow indicates caution or an elevated level of CO, while transitioning from tan to black typically signifies a more critical situation, indicating alarm conditions or high concentrations of carbon monoxide. The presence of both color changes in detector systems allows users to effectively recognize the seriousness of the situation and respond accordingly.

Therefore, the option indicating that CO detectors change colors to both yellow and green as well as tan and black appropriately documents the different signals that these devices may provide, emphasizing the importance of understanding these visual alerts for safety.