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To finish, Matt took questions from his hugely appreciative audience.
One audience member asked why the Simpsons are yellow.
'Yellow wasn't my choice. You initially work in black and white, and one of the animators suggested that we colour them yellow, and it looked right. Then again, she also made the trees purple, which we didn't go for. It means the Simpsons look like no other cartoon characters, though. I don't like that skin colour they use in cartoons. I loved Mickey Mouse when he had a white face, not the strange pink Caucasian colour he is now.'
Source: BBC - Cult - The Simpsons - Matt Groening's Desert Island Flicks
The choice of color for the Simpsons characters was very strategic, actually. As soon as Matt Groening, creator of The Simpsons, was given a drawing of the characters in yellow by an animator, he knew it was perfect.
The idea was that whenever someone was flipping through the channels, they would automatically know The Simpsons was on when they saw the yellow bodies flash by. Speaking of characters, all of them are a digit short of a full, human-like hand. Actually, the only character to ever have five fingers on a hand was God.
Source: Ever wondered why the Simpsons are yellow? - OMG Facts