Double Denim Bar Crawl?

On April 9th, Chicago residents took part in the 3rd annual “Double Denim” bar crawl. The crawl took place at various local bars and invited the patrons to dress up in their best double denim ensembles. The patrons donned their denim and traveled from bar to bar, enjoying drink specials, while mingling with other denim-clad bar goers.

I’ve never heard of such an event, but it sounds quite similar to an “Ugly Christmas Sweater” party. Has anyone ever been to a denim themed party or event? Or did anyone attend the Chicago event?