The Standard Of The Legion
The Vexillum Legionis is an adaptation of the standard of the Roman Legion. The eagle which surmounted the standard is replaced by the Dove, the emblem of the Holy Spirit. Beneath the Dove a cross-bar bears the inscription “Legio Mariae” (Legion of Mary). Intermediate between cross-bar and staff (and joined to the former by a rose and a lily) is an oval frame bearing a representation of the Immaculate Conception (the Miraculous Medal). The staff is set in a globe which, for use on a table, stands on a square base. The whole design conveys the idea that the world is to be conquered by the Holy Spirit acting through Mary and her children.
The Colour Red
It is a picturesque circumstance that the colour of the Legion is red, and not, as might be expected, blue. This was determined in connection with the settling of a minor detail, that is the colour of Our Lady's halo in the vexillum and in the tessera picture. It was felt that Legion symbolism required that Our Lady be shown as full of the Holy Spirit, and that this should be denoted by making her halo of his colour. This drew with it the further thought that the Legion's colour should be red. The same note is struck in the tessera picture, which depicts Our Lady as the biblical Pillar of Fire, all luminous and burning with the Holy Spirit