Left: comparison between the observed (black) and best-fit simulated (green) kernel (top) and cumulative (bottom) distributions of Δ_{F606W, F322W2}. Middle: [Fe/H] histogram that best reproduces the observations of Boötes I. The dashed black and gray distributions are from a spectroscopic survey from Jenkins et al. (2021) and Longeard et al. (2022), respectively. Right: comparison between the observed (top) and simulated (bottom) CMDs, zoomed in on the MS region used to infer the metallicity distribution. The colors of the simulated stars indicate their iron abundance, as shown in the middle panel.