I saw this great Mohonk Shoe by PF Flyers at one of my favorite Portland stores, Local 35, but they are also available through their online store, or they have a great store locator on their website. When possible, support your local shops!
These fun mustard slip-ons by Tod's are available at Nordstrom. Although they are more casual in nature, you can see by the purple example above that they can easily be dressed up or down.
Salvatore Ferragamo took this trend up a notch and made a beautiful more formal shoe in this blue version. Talk about class! Now THAT'S how to amp it up at the office!