Still searching for dashboard colour adjustment on this part

The CSS you have is setting the background image of the body element. A page has exactly one body and is the element that contains everything else.

To set the background of just one element, you need to change the CSS selector used to identify what element the background-image style should be applied to.
From the screenshot you posted earlier, I think you can use:

<style>
#Master_Control_Buttons  {
    background-image: url("/Pictures/metal_1.jpg");
}
</style>
1 Like