Microsoft appears to be transitioning to a darker color scheme with its latest Windows 8 builds.
The Windows 8 login screen in the latest 8160.0.winmain.111122-1913 build now contains a dark blue coloring, compared to the green color scheme of the Windows Developer Preview. Winunleaked posted a number of pictures on Wednesday showing the login screen changes in recent builds. The latest build, 8160.0.winmain.111122-1913, includes the darkest color scheme yet. The changes could reflect a customization element of Windows 8 or Microsoft’s decision to darken its default theme choice.
The software giant is currently preparing pre-beta builds of Windows 8 and many Microsoft watchers believe a Windows 8 beta may arrive at the Consumer Electronics Show in January 2012. Recently leaked screenshots indicate that Microsoft will allow users to change the Start Screen color and the Start Screen background image in beta copies of Windows 8. Microsoft has previously detailed some other minor improvements to the Windows 8 beta. Users will be able to create, name and rearrange Start Screen groups as well as navigate with the Windows 8 Apps screen in a better way. Microsoft is planning to group applications to make it easier for users to identify them in Windows 8 beta.
Check out the changes in recent builds below.

Windows 8 Developer Preview

Windows 8 post developer preview build

Windows 8 build 8160
Image Credits: Winunleaked