Probity's species is an unnamed species from an unnamed planet that was once engaged in a civil war.
They are human-like with two different skin colors: red and blue.
The different colors of this race are at war with each other. They had a statue of their leader, who is deceased, and the color had worn off, making them unsure whether he was red or blue.
This species shake hands differently with one another; while the Reds shake with their right hands, the Blues shake with their left. Ben found out about this when he tried shaking his right hand with the Blue Leader (who thought that Ben was siding with the Reds as a result), degenerating negotiations with each other.
This species' currency is different for Reds and Blues, with the Blues using hand-cut or polished jewels in their payment transactions, while the Reds use refined precious metals, like gold.
For the most part, the war, from an outsiders perspective, always seems to change the deeper one seems to delve into it.
At first glance, the war is a civil war, only to learn that the combatants are actually trying to defend their territories from encroachment by the opposition (closely affiliated with a Cold War in nature), only to next see that the reason for their war is actually a Crusade: both the combatants aggressively debating over the color of their leader Zabin (whose only statue from the time period left had its paint chipped off over the course of millennia before the series even began).
Afterward, it is discovered that both of the military leaders are only fighting to distract from their races' bad economy; as a result, both leaders refuse to even consider signing a peace treaty in order to end it all. Ben then accidentally knocked over and destroyed the statue of Zabin as Way Big, making the two sides declare war against him and merging their factions as one (a purple army), forcing Ben to leave the planet.