The 2023 outburst light curves and hardness ratio of Terzan 5 X–3. The 2023 outburst began on MJD 60002 (2023 February 27). Upper panel: Light curves from NICER observations (0.5−10 keV, blue points) and MAXI (2−20 keV, black points). Lower panel: Hardness ratio, defined as the count rate ratio between 3.8−6.8 keV and 2.0−3.8 keV. Each data point represents 64 seconds of NICER data, with all bursts excluded. The dashed red lines indicate the type I X-ray bursts observed by NICER, and the dashed green line those observed by Chandra (Heinke et al. 2023).