Stare hard at this photo. Stare really hard. Can you guess what you're looking at? No? Maybe because your eyes aren't working hard enough? Maybe you should squint your eyes? Okay. It's your eyeballs. Your amazing, microscopically-structured eyeballs. Squint harder!
This image of a tartan ribbon is the first-ever permanent color photograph, and it was taken 150 years ago yesterday by the legendary scientist James Clerk Maxwell. So just how did he create colors that would last for over a century and a half?