Dominance diagrams of IoM space of the solar vicinity for the four simulated galaxies analysed. Each progenitor is identified by a specific colour, as indicated in the legend. In these diagrams, the local uniqueness of a colour indicates that the region is mainly populated by particles originating from a single progenitor. On the contrary, regions where particles have different origins are identified by areas with blended colours, proportional to the local contribution of each progenitor. The density variation is logarithmically proportional to the colour opacity. The red line on the left panels indicates the approximate limit of the kinematically selected halo (see Section 3.1).