How can I turn my top menu bar and all the window bars dark?

Is there a way to invert the colors on the menu bar at the top of the screen, as well as the title bars of all the windows is OS X? I have a lot of Terminals open usually, and the the light menu bar stands in the way of the vibe I want.

Solution 1:

You can do this with Obsidian Menu Bar:

Obsidian Menu Bar

A hack that makes your OS X menu bar black. And yes, it blends.
Ready for 10.9.2!

Solution 2:

With OS X Yosemite, you can change a setting in System Preferences so that the menu bar and Dock appear dark.

Go to System Preferences → General and check Use dark menu bar and Dock.

The menu bar looks like this when in Dark Mode:

The Dock looks like this when in Dark Mode: