With Lab regulations being so high as to not remove your protective gear during work hours but still wanting to enjoy the festivities can make cardboard and spray paint quite the handy tool.
I don't think they'll be getting any candy knocking on the boss' door but they will make a few people chuckle

"If only they where as creative in their work as they are with such noisy celebrations" - Dr. Vanren
"I don't know I kind of like it, it really is a enjoyable little joke and it meets the safety requirements!" - Dr. Hanri

Did this one quickly because I really liked the idea once it popped into my head so y'know... theres that