If the footer, content and footer sections are separate (not nested) then any background colour or image won't spill over the sections.
By setting the heights of the html and body to 100% the body will fill the viewport (to the bottom of the screen). You could then use a background colour for the body which will fill the remainder of the page.
But you would need to ensure that each of the preceding sections have no margins and have either a background colour or image - otherwise the body colour will show through these, earlier than you intend. Andy.