Left panel: Median [Fe/H] of the stellar halo (circles) and the accreted stellar halo (triangles) as a function of the galaxies’ total stellar mass. Right panel: Median [Fe/H] of the inner stellar halo between 4 R_h and 6 R_h (stars), and of the outer stellar halo between 6 R_h and 10 R_h (squares) as a function of the galaxies’ total stellar mass. The colour bar represents the total amount of accreted stellar material of the galaxies.