This song by Coldplay from their album Parachutes has has a truly interesting meaning, one explained to me and the rest of the audience by the lead singer, Chris Martin, at their June 2, 2001 performance at the Electricy Factory in Philadelphia. Had I not been at the show to bear witness, I might not believe the story.

Seems he and the guitarist John Buckman set out to score some cocaine one evening and purchased what was supposed to be a box of coke (not sure what quantity this was supposed to be). However, when they got it home and opened the box (you never really check out drugs in front of a dealer), voila! It was filled with custard powder. And the custard powder was yellow.

Makes the lines "I drew a line/I drew a line for you/oh what a thing to do/you were all yellow" seem a bit more sensible, no?