The present disclosure provides a sensor with color-coded indications that various patient physiological parameters are being monitored, such as blood oxygen saturation, blood pressure, respiration rate, and respiration effort. The sensor may sense a physical characteristic used to monitor the physiological parameter, and a visible light emitter emits visible light of a first color that is color-coded to the physiological parameter, but is not used to sense the physical characteristic. The visible light emitter may emit visibly flashing light in response to the sensor sensing a threshold value of the physical characteristic. The sensor may include a second light emitter that may sense the physical characteristic, and may emit light of a second color that is color-coded to a first or second physiological parameter. In some embodiments, the first and second colors may visibly mix. The first and second visible light emitters may emit light independently, including visibly flashing light.