If you're an avid K-pop fan, there's a good chance you have a light stick glowing on your shelf. But even the uninitiated have likely seen pictures of the light sticks that emit vibrant colors and patterns at concerts, fan events and music festivals. K-pop artists each have their own "bong" -- the Korean word for stick -- and it's more than a gleaming accessory. Light sticks reflect a group's official fandom color, logo, theme, identity or a special symbol that represents and connects with their