Idiom. 1. Accusing someone of doing something you are guilty of. 2. Synonymous with "What's your problem?"
1. While eating crackers on the couch, you tell your friend, "Hey no eating on the couch!" Your friend replies, "What's up with your yellow?"

2. You: "Hey Frank!" Frank: "Piss off!" You (disgusted): What's up with your yellow?"
by Slugboy73 August 19, 2007
Get the What's up with your yellow? mug.