Left: UVJ colour diagram. GS-z5-Q1 and COS-z5-Q1 are indicated with full red circles, along with the sources in Weibel et al. (2025), Looser et al. (2024), de Graaff et al. (2025b) as labelled. The background grey-scaled sources are QG candidates at z > 2 from Baker et al. (2025d), where the mass cut has been relaxed (M_★ > 10^9.3 M_⊙). Right: Same galaxies as on the left are shown in the stellar mass versus redshift plane. Quiescent galaxies with JWST medium/high-resolution spectra compiled in Ito et al. (2025a) are also shown in squares. It highlights how low-mass GS-z5-Q1 and COS-z5-Q1 are compared to the de Graaff et al. (2025b) galaxy at z = 4.9, i.e. almost 1.5 dex less massive, despite having similar colours and redshifts.