Credit:
Custom label colors lets you, well, choose custom colors for your labels, giving you far more options than the standard 24 color combinations.
Go to label keyboard shortcut adds a new shortcut combination to Gmail; press "g" then "l" to display the "Go to label" pop-up. If you're into shortcuts, you might want to check one of our older lists with many keyboard shortcuts for various online applications.
The last option, Navbar drag and drop, lets you reorder the items in Gmail's lefthand navigation bar by dragging and dropping.