Launch Party - S4-E3
Revealing mistake: In the first scene, everyone is in the conference room, just waiting for the block on the TV to hit a corner while Michael is blabbing away. The screen has no reflections, but later when Michael talks to the camera there is a reflection. In the scene you can also see the off shading on the characters in it, making it very apparent that the scene was filmed using a green screen.
Answer: In the 2007 episode "Ben Franklin" when Jim is talking to Pam there is a candy bar with a purple wrapper that says "Picar-" I assume picaroon, it's hard to see past Pam. I found this trying to investigate what that candy bar is lol.