This shows buttons that are bright and bold can stand out on a dark background. Designer: Ryan Johnson Source: Dribbble
This power button shows how lighting and can be used to give the button a 3D look that beckons to be pushed. Designer: Pontus Johansson Source: Dribbble
This is a great example of dark ui elements done correctly. Designer: Lukas Majzlan Source: Dribbble
Designer: Steinar Ingi Farestveit Source: Dribbble
This combination of Google maps and clean icons provide an excellent user experience.
A very clean design with a great minimal colour palette.