Your Black, (You killed Gray's father when he was young and adopted him I'm to tired to explain in detail) after years of suffering and loneliness. Gray go rouge. He takes his machete and start looking for the other impostors. (You have a parasite form that is much stronger than your normal form)

Red is talking with Green in the cafeteria

White fell asleep watching the cameras

Maroon is doing knife tricks alone in storage

Pink is listening to music in the greenhouse

You are cleaning your knife in your room. Oblivious to what Gray is about to do