Advanced Appearance Settings, Change the background to gray color.

Advanced Appearance Settings

Windows 8 & 8.1
* From the Metro UI (or press the WINDOWS key on your keyboard), search for regedit (be sure to type the entire word!)
* Press CTRL + SHIFT + ENTER to run this program with administrator privileges, or right-click the regedit application that appears as a search result on the left and select "Run as administrator" on the bottom panel
* Using the navigation panel on the left, click into HKEY_CURRENT_USER -> Control Panel -> Colors
* Scroll down on the right panel to the "Window" entry and double-click on it
* Change the "Value data" to the RGB values for a gray color, such as 192 192 192 or you can go higher all the way to 216 216 216 which will give you a lighter shade of grey (you may adjust to your preference)
* Save all your work and restart your computer