The flag of Tyrravias
The people of Tyrravias have always been extremely proud of their nation. That of course can be said about most nations, and while we don't know whether the people of Tyrravias were extraordinary proud of their nation or something, when someone said that the concept of nationalism originated from Tyrravias, it stuck. That is why the color red represents nationalism, it was the only color without a suitable explanation. The purple represents the king, and this time doesn't also represent the queen, for that's represented by the pink. The queen always sat at the left side of the king in Tyrravias, and other nations adopted this idea. That's why the pink is at the left side of the purple. The king clearly stands above all, the purple is in front of every color (except for the brown of Tyrravias, but how can a king be more important than the nation he rules for the common citizen). And the king is associated with a new dawn and a brighter future and all those things the traditional Ptolemaic sun represents. At the right of the purple, we have gold, and gold represents honor, or so it is believed, because the place at the right side of the king was 'the place of honor', reserved for honorary guests and such. There are multiple theories about what the checkered stripe represents. Perhaps it represents all the nations in the world, and seeing as the red (nationalism) is palced on top of it just like the king, this could further enforce the idea of nationalism. We are more important than those other nations. That theory is generally believed to be true, and if that's true, than the squares perhaps are black and white because they are dull colors, uninteresting colors. Remember, we are the most important nation, why should we value those other nations, why would we be interested in them? But let it not be said that the people of Tyrravias were stuck-up, arrogant, and egoistic, for that simply wasn't (and isn't) true
The flag of Tyrravias under the Kingdom of Bruis
While the people of Tyrravias were proud, very proud, of their nation (indeed, they adored their king as if he was a god, from which possibly the concept of God-King or God-Emperor originated, that the king was possessed by a god and that he was subject to no earthly authority, that he was only accountable to god), when they were annexed by the Kingdom of Bruis, the king of the Kingdom of Bruis promplty became their God-King, and as proud they were of Tyrravias, so proud they were of the Kingdom of Bruis. It is remarkable that instead of only adding a border around the flag, the Kingdom of Bruis replaced the gold with its own brownish red color, thus giving the impression that the Kingdom of Bruis was a vassal or something of the king of Tyrravias (which of course no longer existed), while in fact it was the other way round.
Another version of the flag of Tyrravias under the Kingdom of Bruis
Later (much later, by historians in fact), it was discovered that perhaps originally, the Kingdom of Bruis wanted to use another flag for Tyrravias, one which had a smaller, dark brown circle on top of the purple one, giving the impression that the king of Tyrravias (which, again, no longer existed) was under the command of the Kingdom of Bruis (which was true though). However, perhaps deciding that the people of Tyrravias wouldn't like that very much, the Kingdom of Bruis apparently chose another flag.