Left: difference between proper motions in declination and median value (top) and scaled (bottom) to the nominal uncertainties as a function of G for the whole cluster sample. The solid lines indicate the LOWESS of the sample; blue corresponds to stars bluer than G_BP − G_RP = 0.9 mag and red is for objects redder than this limit. Right: colour-magnitude diagram of the whole cluster sample where the colour indicates the difference between the star μ_δ and the cluster median. The rightmost panel is analogous to the left-hand panel, where the difference is scaled to the nominal uncertainties.