Colours

Simon heard gasps, hushed whispers and even a shout, though he could not see the source of the commotion, someone who had just entered the room according to {the good friend}’s mutter. Quickly, the mingling crowd hurried to part way for a young man–dressed in blinding white.  “If he intended to offend everyone in the room, then he did exceedingly,” {the friend} remarked. “Who’s that lunatic?”

Things that had come into contact with the Particles, including people who died from the radiation, turn white. Therefore, white is associated with death and danger. Wearing white can even be seen as an offence.
On the other hand, black seems to repel the Particles, so it's associated with safety and protection. Protective gear and hazmat suits are all black.