Denim on denim used to mean Britney and bedazzled, but the former fuss has been replaced by a sumptuous spin on classic workwear. Denim button-up shirts paired with jeans are seen returning to rich indigo hues, touched with patches, and rolled-up at the sleeves. There's a similar spirit to the 60s Berkeley students or folk singers' dress, who'd sport the blue collar look to celebrate solidarity. Here, though, it's modernized with the MacBook accessory instead of a guitar for sharing forward-thinking thoughts. We've captured looks in Paris, Milan, London, and Seoul.