Windows 8 How To . . .
Change the Start Screen Colour
First click on the icon or picture in the top right of the screen
Click "Change account picture" and click "Start Screen" just above the users picture.
Select the colour and design you like
Close the screen by moving the cursor to the top of the screen until it changes to a hand, click and hold the mouse button and drag to the bottom of the screen, let go of the mouse or press Alt and F4.