Absolute magnitude vs. reddening-free colour obtained from TRILEGALv1.6 simulations. Crosses represent simulated stars from a total area of 100 square degrees in the NPF and the SPF, satisfying the conditions described by the labels at the top of each plot. The left and right panels also show the analytical selection (red lines) described in Sect. 3.3 for FGK dwarfs and subgiants (FGK sample) and for M dwarfs (M sample), respectively. In the diagram on the right, the blue dashed line represents a 10 Myr solar metallicity isochrone from the Padova database (Bressan et al. 2012).