If I told you my house were the only blue one on the block, you'd know how to find it. Whether it were powder or navy blue, our shared understanding of "blue" means we can communicate about color. Paul Kay, a researcher at the University of California, Berkeley, wants to know exactly what that means to our brains. Are we thinking about the color blue or the word we use to represent it? Do the words we use influence the way we see the colors themselves? According to Kay, those two ideas may by inextricably connected inside our heads.