Comparison of the color distributions of unresolved sources in Rubin DP1 (the shaded gray regions bounded by solid black lines represent ±2σ envelope around the median color in g − i bins) and stellar model color sequences from Palaversa et al. (2025). The sequences correspond to a 10 Gyr population are color-coded by metallicity; the full metallicity range is −2.5 < [Fe/H] < +0.5 and coded linearly from blue to red (for additional details, see Fig. 3 in Palaversa et al. 2025).