In the map the giant your starting pistol has green lights on it and when you stand in just the right spots and aim in precise locations it changes the color on the pistol from green to yellow. I really feel confident this has nothing to do with surrounding lights nor do i think light bug in the game.
Heres the link to the reddit where i originally found this info and a video for proof
I felt like it was to easily looked past on reddit hopefully this vast community can help
https://www.reddit.com/r/CODZombies/comments/3xdf9d/starting_pistol_on_the_giant_lights_up_yellow/
I can confirm that i have done this myself in the location in the video and found a couple other (2).
Thank you for your time
