The background uploader you’re using is for the entire site, instead I would just directly add the background color to the section that you want it to show up in. Example, if you want the middle section of your homepage to show a certain color/image, then you can add something like this –
.middle-section {
background: #ff0000;
}
You can replace the above code and add a color or a link to a background image if you want.
Is the middle section the part of the homepage you’re trying to change?