Metallicity distributions (log Z) for BCGs (red), stellar halos (black), and ICL (blue) at z = 0 (left panel) and z = 2 (right panel), similar to Figure 6. In both panels, stellar halos and the ICL exhibit broadly comparable distributions, whereas BCGs remain systematically more metal-rich than the other two components, regardless of redshift. The separation is present at all epochs, but appears much more pronounced at z = 2. The brown line at z = 0 represents the observed distribution in FDS (SHs).