Krispy Kreme is bringing back a fan-favorite doughnut, and fans can get one for free. They’ll have to dress the part, though. Starting Saturday, March 15, anyone wearing green can get a free O’riginal Glazed doughnut at participating Krispy Kreme shops nationwide, according to the Charlotte-based doughnut chain.

Krispy Kreme on Monday launched an all-new doughnut collection inspired by St. Patrick's Day. Here's a look at the new flavors.

It's hard to argue that Krispy Kreme (NASDAQ: DNUT) doesn't sell tasty treats that consumers love. It's a bit more of a stretch, however, to convince investors that the donut slinger's stock is an attractive investment.