Hertzsprung–Russell diagram of the sample of clusters. The colored filled dots represent GES targets retained after the procedure of cleaning from the obvious contaminants. The spectroscopic candidates color-coded depending on the probability of belonging to the cluster (scale at right). The magenta and blue lines are the isochrones at 20 and 50 Myr, respectively, and the black and red lines are the PMS evolutionary tracks (Tognelli et al. 2011).