Left panel: OB runaways originating in Vel OB1 and the candidate members of Vel OB1 (neither has been corrected for interstellar extinction) plotted in the colour-absolute magnitude diagram of RCW 38. The OB runaways associated with a wind bow shock (black triangles) are more reddened than those without a bow shock (green triangles). The red arrow represents the dereddening vector. The PARSEC isochrones (dashed lines) are shown for an adopted reddening of A_V = 3 mag. Right panel: OB runaways and the candidate members in the HRD (with the effective temperature based on spectral type, luminosity based on distance, bolometric correction included, and corrected for extinction). The red line represents the zero-age main sequence from the solar metallicity grid in Maíz Apellániz (2013); the dashed lines are PARSEC isochrones corresponding to the age indicated in the legend. The location of the OB runaways suggests that most of them are still in the hydrogen-burning phase; some others are on their way to become a red supergiant.