Panel a: (m_F275W, m_F275W–m_F438W) CMD of all the stars in common between the ACS and WFC3 catalogues; panel b: CMD of all the likely contaminating objects as selected from the VPDs; panel c: relative PM-cleaned CMD obtained by using only likely cluster members; panels d: VPDs at different magnitude levels. The solid red circle represents the fiducial region used to select likely cluster members.