Frontpage: change background color around text box

I’m looking for a way to make the background surrounding a frontpage text box a different shade, such as light grey, while keeping the text box background white. Any suggestions?

First, go to the row options and change full width to default for the row containin g the text (in the Page Builder).
Then add this in a custom CSS plugin: .site-content {
   background-color: #D8D8D8;

That’s great, I added it. However, it looks as if there’s about 5px of padding that leaves a thin white stripe between header image and page content. Can I make that go away? Alternatively, could I add padding above and below the text box in the background color so that the grey frames it all around? Not sure which way I want to go…

Use this and adjust to your needs: .site-content {
   padding-top: 50px;
   padding-bottom: 50px;
img {
   vertical-align: middle;

Following up on this request: I would now like to apply this same appearance to all the other pages.

I used the Front Page template for all pages, and the Page Builder for all page content, so how would I modify the CSS to get the gray background and text box around the text? Thanks!