im going to sound crazy and like an insane person but;
was rewatching the cannablism arc and this scene,
Notice how the only people who have light on their face/hair are Tanizaki and Tachihara?(Gin has a little bit on the tip of her long hair strip but that's unrelated) Tanizaki is a member of the ADA, and so he has half of his hair with light and the other half in dark which represents the fact that while he is on the light side, he has darkness inside of him. Tachihara is a government spy and a hero of justice, however the dark on his face and hair represents his darker side and how he's beginning to/how he does care about the mafia just as much as he cares about the hunting dogs.
"but that's just the lighting-" ik. but it's cool that in a way it kinda shows whose on the side of the light :D
