Google Analytics is rolling out a new design for their navigation and sidebar. The new design is less bright orange and more gray/white.
Google Analytics said on Google+:
Some of you may have noticed a shiny new nav and sidebar inside of Analytics. If you're not seeing it yet, you will over the next few weeks. We think this is a simpler and more beautiful way to present your reports, dashboards and will make your analysis easier and faster. See a quick preview below.
Here is an animated GIF of the before and after:
Many of you should begin seeing the new look shortly.