As Steve Jobs famously said, most people make the mistake of thinking “design” is about how something looks, rather than how something works. But how a product looks can play a key role in how that product works. Visual design is a complex subject, often one without easy explanations. The video below asks a simple question — why are so many cartoon characters (think Bart Simpson) yellow? While the creation of each individual character can provide a different story, there are some general principles that come into play. Color theory, for example, shows us that on the RGB color wheel, yellow is complementary to blue, and given that blue is a common background color (the sky, the sea), a yellow character will stand out well against it. Color psychology plays a role (yellow is a warm color, and seen as “active”), as do the physical properties of the human eye.