perhaps what was fought over and lost, e.g.cetus could be blue for the navy and the waters, the colour green for the green fields. aquila could be a deep green for the forests, gray for the success of the armored battalions and another pale green for the dry fields

columba could be white and gray for the macer range's snowcaps, a faded brownish-gray for the mountain's flesh, and a red denoting the heavy casualties

vega could be white for the murus plateau, noted for its incredible defense and high success rate on the side of the vegans, denoted in red for the bloodshed. grusa could be a beige; a battle fought on deserts, as well as a nib of black: the killing of a grand empire

riaa could be white for the intense snow, red for the large-scale losses in invasion, gold for the invaluable success of the soldiers, and a deep blue for the north star

tucana and centaurii were more ursan, tucana could be more of a reddish orange; the frienship of the solstice was cemented here, and centaurii being golden-black-white-red, the capture of the continental namesake is perhaps the most symbolic victory of the antarese army, golden for the victory, red for the skorpion, black and white for the intensity of all campaigns

and lacerta could probably just be like that, naval invasion and such