Proper motion selection of Terzan 5 members. Panels a and b: optical CMDs (m_F606W - m_F814W, m_F814W). Panels c and d: NIR CMDs (m_F115W - m_F200W, m_F115W). The left panels in each row show all the stars that satisfy the photometric-quality criteria in black, while panels b and d highlight only those classified as likely cluster members from the proper motion analysis in red. The horizontal dashed lines mark the m_F814W magnitude bins adopted in the proper motion selection. The panel in the upper right shows the corresponding VPDs for each magnitude interval: in each subpanel, the red dots mark stars retained as members and the black dots indicate rejected (Galactic field) sources. The effectiveness of the proper motion membership selection is clearly demonstrated by the rejection of Galactic field MS stars drawing the evident blue plume (bluer and brighter than Terzan 5’s MS-TO) in panels a and c.