[Fe/H] distribution of the metal-rich GCs that are chemically compatible with ω Cen; namely NGC 6752, NGC 6205, and NGC 6254. For comparison, in each plot, the [Fe/H] distribution of ω Cen (NGC 5139) reported in Johnson & Pilachowski (2010) is also shown (black step-like histogram). The latter has been normalised in such a way that the secondary peak value coincides with the maximum of the [Fe/H] distribution of the cluster to which it is compared.