Color-Coded for Your Convenience, Red Eyes, Take Warning: In-universe. Their eyes grow yellow when then they become evil (orange for the really evil) and blue or gray when they become good. They even use this trait to determine prison terms - a criminal stays in prison until their eye grows green at least.
Космические пираты Крыс и Весельчак У (Space pirates Rat and Jolly U)
Enemy Mine: Used to be enemies before the police busted most of their operations. Their current alliance is built on nothing but convenience, and they state openly they'll betray each other without hesitation.