how to Clear the desktop icons background color?

Try this 3 methods

1.Remove all Active desktop items :
-Right click Desktop
-Properties
-Desktop tab
-'Customize desktop' button
-Web tab
-Uncheck all items and click OK twice.

2. Uncheck Lock icons :
-Right click Desktop
-Point to Arrange icons by
-Uncheck "Lock web items"

3. Enable 'Use Drop shadows for icons' :
-Click Start > Run
-Type sysdm.cpl ,3
-Press Enter or Click OK
-Click the first "Settings" button (under Performance)
-Scroll down and tick "Use drop shadows for icon labels."
-Click OK twice.