How to customize my Desktop Colour

Hello Every one. Please i need help on how to change the colour of my Desktop from the usually blue or so. I used firebug on my browser, and the location there shows the style is in an html file with title ‘desktop’. But the problem is i don’t know where to locate it. Please help. Thanks

Hello! try going to my settings > Desktop Background > and upload a image. then go and press reload.

@Randy_Lowery Thanks alot. It was that simple. But this only affects the desktop of that particular user. I want to edit the style from the code itself to change the colour from blueish to greenish or so. How do i locate the file on my server. Thanks