We wanted something simple to remember, which is why we went with icons or symbols … I gave each symbol a meaning and a color. The triangle refers to viewpoint; I had it represent one’s head or direction and made it green. Square refers to a piece of paper; I had it represent menus or documents and made it pink. The circle and X represent ‘yes’ or ‘no’ decision-making and I made them red and blue respectively.

Why Playstation Controller Buttons Are Symbols, Not Letters (via Instapaper)