Rotation period vs. V-K (corrected for reddening for the Pleiades) for TOI-942 (large black filled circle), and members of the Pleiades (red circles); IC 2391 (blue squares); Tuc-Hor, Columba and Carina associations (green triangles); and β Pic MG (purple upside-down triangles). References for rotation periods: Pleiades: Rebull et al. (2016); IC 2391: Messina et al. (2011), Desidera et al. (2011); Tuc-Hor, Columba, and Carina: Desidera et al. (in prep.), Messina et al. (2010, 2011); β Pic MG: Messina et al. (2017).